USC.edu

Stephan Haas

Professor of Physics and Astronomy
Stephan Haas
Email shaas@usc.edu Office SSC 211A Office Phone (213) 740-4528

Research & Practice Areas

condensed matter theory, interacting and disordered many body systems, quantum magnetism, unconventional superconductivity, quantum information theory.

Center, Institute & Lab Affiliations

  • USC Center for Quantum Information Science and Technology, Deputy Director

Biography

Stephan Haas was born in Berlin and spent his early years in both Germany and Japan, gaining exposure to diverse cultural and educational environments. He began his academic journey in physics at the Technische Universität Berlin, where he earned his Vordiplom in Physics in 1990. To further his studies, Stephan moved to the United States and completed his Ph.D. in Physics at the National High Magnetic Field Laboratory at Florida State University in 1995, focusing on theoretical quantum systems.

Following his doctorate, Stephan undertook a postdoctoral fellowship at the Swiss Federal Institute of Technology (ETH Zurich), where he expanded his research into quantum condensed matter physics. In 1998, he joined the faculty at the University of Southern California (USC), where he has been a member of the Department of Physics and Astronomy.

At USC, Stephan Haas and his research group focus on topics including quantum magnetism, superconductivity, and quantum information theory. Their work investigates microscopic models of interacting quantum systems, employing numerical techniques like Quantum Monte Carlo, Renormalization Group, and Exact Diagonalization to explore phase diagrams, ground states, and dynamical properties. Recently, his research has focused on the effects of interactions and disorder in topological quantum systems.

Education

  • Ph.D. Physics, Florida State University, 1995
  • M.A. Physics, Florida State University, 1993
  • Vordiplom Physics, Technische Universitat Berlin, Germany, 1989
    • Postdoc, ETH Zurich, 1995 – 1998

  • Tenure Track Appointments

    • Professor, University of Southern California, 02/03/2006 –
    • Associate Professor, University of Southern California, 01/01/2002 – 02/03/2006
    • Assistant Professor, University of Southern California, 01/01/1998 – 01/01/2002
    • Post-Doctoral Associate, Theoretische Physik, Switzerland, 01/01/1995 – 01/01/1998
    • Research Assistant, Florida State University, 01/01/1991 – 01/01/1995
    • Teaching Assistant, Florida State University, 01/01/1990 – 01/01/1991

  • Summary Statement of Research Interests

    Stephan Haas’s research focuses on quantum phase transitions, superconductivity, and nanotechnology. His group studies microscopic models of interacting electronic systems, using numerical techniques to explore their phase diagrams, thermodynamic properties, and excitation spectra.

    His research in quantum magnetism involves examining phase diagrams, excitation spectra, and thermodynamic properties of quantum magnets. The group uses numerical simulations, such as Quantum Monte Carlo and exact diagonalization, to study impurity and field-induced magnetic order in quantum spin liquids.

    The group’s work on superconductivity focuses on unconventional superconductors with nodal order parameters. They apply a generalized BCS mean field theory to investigate properties of cuprate, organic, and heavy-fermion compounds. Recent studies include Gossamer phenomena, where two unconventional order parameters coexist.

    In nanotechnology, the group develops adaptive quantum design algorithms to identify optimal spatial configurations of nanoscale building blocks, such as atoms and molecules. These algorithms have been used to tailor quasiparticle density of states in atomic clusters, design dielectric structures with specific transmission profiles for photonics, and engineer many-body wave functions in quantum wells.

    The group examines quantum phase transitions through entanglement measures, like the von-Neumann entropy. Using Quantum Monte Carlo simulations, they study the scaling behavior of block entropy across quantum critical points and compare multipartite and bipartite entanglement in many-body systems.

    Their research on topological quantum systems explores the effects of interactions and disorder on these systems, leading to complex phase diagrams with multiple topological sectors. The group also studies the dynamics of these systems, including simulations on quantum hardware, with an eye toward potential technological applications.

    Overall, the research is strongly connected to current experimental efforts in quantum antiferromagnetism, high-temperature and heavy-fermion superconductivity, and nano-photonics. By bridging theoretical studies with experimental findings, the group aims to contribute to the understanding and development of new quantum materials and technologies.

    Research Keywords

    condensed matter theory, interacting and disordered many body systems, quantum magnetism, unconventional superconductivity, quantum information theory.

    Research Specialties

    condensed matter theory, interacting and disordered many body systems, quantum magnetism, unconventional superconductivity, quantum information theory.

    Detailed Statement of Research Interests

    Our research group focuses on several key areas of condensed matter physics, including quantum magnetism, superconductivity, and nanotechnology. We investigate the behavior of microscopic models of interacting electronic systems to uncover their phase diagrams, ground state properties, and excitation spectra. To achieve this, we utilize a variety of advanced numerical techniques, such as Quantum Monte Carlo simulations, Exact Diagonalization, and the Stochastic Series Expansion Method. Our work is motivated by and closely connected to recent experimental findings in fields like quantum antiferromagnetism, high-temperature superconductivity, heavy-fermion systems, and nano-photonics.

    One of our primary areas of interest is quantum magnetism. Here, we focus on understanding the complex phase diagrams, excitation spectra, and thermodynamic properties of quantum magnets. Using Quantum Monte Carlo simulations and exact numerical diagonalization, we explore phenomena such as impurity and field-induced magnetic order in quantum spin liquids. Recently, our work has concentrated on studying field-induced phase transitions in these systems, contributing to a deeper understanding of their behavior under various conditions.

    Superconductivity is another central theme of our research. We are particularly interested in unconventional superconductors and density wave states with nodal order parameters. Our group applies a generalized BCS (Bardeen-Cooper-Schrieffer) mean field theory to investigate the properties of materials such as cuprates, organics, and heavy-fermion compounds. We are also exploring Gossamer phenomena, where two unconventional order parameters coexist, offering insights into the interplay between different types of order in strongly correlated systems.

    In the realm of nanotechnology, our research focuses on adaptive quantum design. We are developing algorithms that identify optimal broken-symmetry spatial configurations of nanoscale building blocks, such as atoms and molecules, to achieve desired functional responses. These techniques have been applied to tailor the quasiparticle density of states in atomic clusters, design dielectric structures with specific transmission profiles for photonics, and engineer many-body wave functions in quantum wells for excitonic modulators. This work is integral to the advancement of nano-scale opto-electronic devices.

    Our group also explores quantum information theory, particularly the role of entanglement in characterizing quantum phase transitions in many-body systems. By studying the scaling behavior of block entropy across quantum critical points using Quantum Monte Carlo methods, we aim to gain insights into the nature of quantum entanglement. We also compare multipartite and bipartite entanglement, enhancing our understanding of quantum correlations. Additionally, we are investigating kinetic receptor models to describe the transport of spikes across neural synapses, bridging our research with concepts from neuroscience.

    Finally, we are exploring topological quantum systems, investigating how interactions and disorder influence their phase diagrams and dynamics. This research has implications for understanding the complex behavior of topological phases, including potential applications in quantum technologies. We are particularly interested in simulating these systems on quantum hardware, which could open new avenues for studying and manipulating topological states in practical settings.

    Overall, our research is deeply integrated with experimental efforts across various domains, aiming to bridge theoretical models with real-world phenomena. By advancing our understanding of quantum materials and their properties, we hope to contribute to the development of new technologies and the broader field of condensed matter physics.

    • (Fall 2020) PHYS 172. Applied Physics II: Electricity, Magnetism and Optics, MW, 10:00am – 10:50am, ONLINE
    • (Fall 2021) PHYS 172. Applied Physics II: Electricity, Magnetism and Optics, MW, 10:00am – 10:50am, ONLINE
    • (Fall 2022) PHYS 540. Solid State Physics, TTh, 10:00am – 11:50am
    • (Fall 2023) PHYS 438B. Introduction to Quantum Mechanics and its Applications, TTh, 08:00am – 09:50am, KAP158
    • (Fall 2024) PHYS 152. Fundamentals of Physics II: Electricity and Magnetism, TTh, 09:30am – 10:50am, SLH200
    • (Spring 2025) PHYS 152. Fundamentals of Physics II: Electricity and Magnetism, TTh, 02:00pm – 03:20pm, SLH200
    • current topics: fidelity measures of quantum information theory applied to quantum phase transitions, crossover from quantum mechanics to classical physics in nanostructures, quantum glass phases in disordered Heisenberg models

  • Book

    • Levi, A., Haas, S. (2009). Optimal Device Design. Cambridge: Cambridge University Press.

    Book Chapters

    • Zhang, W., Haas, S. (2010). Switching Mechanism in Ferromagnetic Nanorings. Handbook of Nanophysics (Vol. 40-1) CRC Press, Taylor & Francis.

    Journal Article

    • Haas, S., Mercado, M., Chen, K., Darekar, P. H., Nakano, A., Felice, D., R., H. S. (2024). Dynamics of symmetry-protected topological matter on a quantum computer. Physical Review. Vol. B (/Physical), pp. eview. B, 110(7). https://doi.org/10.1103/physrevb.
    • Wu, J., Yao, Y., Lin, M. L., Rösner, M., Du, Z., Watanabe, K., Taniguchi, T., Tan, P. H., Haas, S., Wang, H. (2022). Spin-Phonon Coupling in Ferromagnetic Monolayer Chromium Tribromide. Advanced materials (Deerfield Beach, Fla.). Vol. 34 (20), pp. e2108506. PubMed Web Address
    • Courcoubetis, G., Xu, C., Nuzhdin, S. V., Haas, S. (2022). Avalanches during epithelial tissue growth; Uniform Growth and a drosophila eye disc model. PLoS computational biology. Vol. 18 (3), pp. e1009952. PubMed Web Address
    • Courcoubetis, G., Gangan, M. S., Lim, S., Guo, X., Haas, S., Boedicker, J. Q. (2022). Formation, collective motion, and merging of macroscopic bacterial aggregates. PLoS computational biology. Vol. 18 (1), pp. e1009153. PubMed Web Address
    • Song, B., Jiang, Z., Liu, Z., Wang, Y., Liu, F., Cronin, S. B., Yang, H., Meng, D., Chen, B., Hu, P., Schwartzberg, A. M., Cabrini, S., Haas, S., Wu, W. (2020). Probing the Mechanisms of Strong Fluorescence Enhancement in Plasmonic Nanogaps with Sub-nanometer Precision. ACS nano. Vol. 14 (11), pp. 14769-14778. PubMed Web Address
    • Courcoubetis, G., Ali, S., Nuzhdin, S. V., Marjoram, P., Haas, S. (2019). Threshold response to stochasticity in morphogenesis. PloS one. Vol. 14 (1), pp. e0210088. PubMed Web Address
    • Ngo, Y., Wang, Y., Haas, S., Noskov, S. Y., Farley, R. A. (2016). K+ Block Is the Mechanism of Functional Asymmetry in Bacterial Na(v) Channels. PLoS computational biology. Vol. 12 (1), pp. e1004482. PubMed Web Address
    • Yeshwanth, S., Rigol, M., Haas, S., Venuti, L. C. (2015). Small quench dynamics as a probe for trapped ultracold atoms. PHYSICAL REVIEW A. Vol. 91 (6)
    • Ngo, V. A., Di, R., Haas, S. (2014). Is the G-quadruplex an effective nanoconductor for ions?. The journal of physical chemistry. B. Vol. 118 (4), pp. 864-72. PubMed Web Address
    • Ngo, V., Stefanovski, D., Haas, S., Farley, R. A. (2014). Non-equilibrium dynamics contribute to ion selectivity in the KcsA channel. PloS one. Vol. 9 (1), pp. e86079. PubMed Web Address
    • Ngo, V., Wu, H., Haas, S., Farley, R. (2014). Mechanism of Non-Selectivity in NAK Channel. BIOPHYSICAL JOURNAL. Vol. 106 (2), pp. 558A-558A.
    • Tabbakhian, M., Ngo, V., Haas, S., Farley, R. (2014). Amino Acid Substitutions for T75 in KCSA Alter Ion Selectivity. BIOPHYSICAL JOURNAL. Vol. 106 (2), pp. 539A-539A.
    • Vasseur, R., Trinh, K., Haas, S., Saleur, H. (2013). Crossover physics in the nonequilibrium dynamics of quenched quantum impurity systems. Physical review letters. Vol. 110 (24), pp. 240601. PubMed Web Address
    • Chancellor, N., Petri, C., Haas, S. (2013). Non-Markovian equilibration controlled by symmetry breaking. PHYSICAL REVIEW B. Vol. 87 (18)
    • Venuti, L. C., Yeshwanth, S., Haas, S. (2013). Equilibration times in clean and noisy systems. PHYSICAL REVIEW A. Vol. 87 (3)
    • Song, K. W., Liang, Y., Lim, H., Haas, S. (2013). Possible nematic order driven by magnetic fluctuations in iron pnictides. PHYSICAL REVIEW B. Vol. 88 (5)
    • Trinh, K., Haas, S. (2013). Bond disorder in even-leg Heisenberg ladders. PHYSICAL REVIEW B. Vol. 87 (7)
    • Ngo, V., Stefanovski, D., Farley, R., Haas, S. (2013). Thermal Effects and Free-Energy Barrier Differences in the Ion Selectivity Mechanism of KcsA. BIOPHYSICAL JOURNAL. Vol. 104 (2), pp. 128A-128A.
    • Ngo, V. A., Haas, S. (2012). Demonstration of Jarzynski’s equality in open quantum systems using a stepwise pulling protocol. Physical review. E, Statistical, nonlinear, and soft matter physics. Vol. 86 (3 Pt 1), pp. 031127. PubMed Web Address
    • Yu, R., Yin, L., Sullivan, N. S., Xia, J. S., Huan, C., Paduan-Filho, A., Oliveira, J. r., Haas, S., Steppke, A., Miclea, C. F., Weickert, F., Movshovich, R., Mun, E. D., Scott, B. L., Zapf, V. S., Roscilde, T. (2012). Bose glass and Mott glass of quasiparticles in a doped quantum magnet. Nature. Vol. 489 (7416), pp. 379-84. PubMed Web Address
    • Chancellor, N., Haas, S. (2012). Using the J(1)-J(2) quantum spin chain as an adiabatic quantum data bus. NEW JOURNAL OF PHYSICS. Vol. 14
    • Chang, Y., Albash, T., Haas, S. (2012). Quantum Hall states in graphene from strain-induced nonuniform magnetic fields. PHYSICAL REVIEW B. Vol. 86 (12)
    • Ngo, V. A., Haas, S. (2012). Demonstration of Jarzynski’s equality in open quantum systems using a stepwise pulling protocol. PHYSICAL REVIEW E. Vol. 86 (3)
    • Song, K. W., Liang, Y., Haas, S. (2012). Excitonic instabilities and insulating states in bilayer graphene. PHYSICAL REVIEW B. Vol. 86 (20)
    • Trinh, K., Haas, S., Yu, R., Roscilde, T. (2012). Correlations in quantum spin ladders with site and bond dilution. PHYSICAL REVIEW B. Vol. 85 (3)
    • Das, A., Garnerone, S., Haas, S. (2011). Entanglement and its evolution after a quench in the presence of an energy current. Phys. Rev. A. Vol. 84, pp. 052317.
    • Vedadi, M., Haas, S. (2011). Mechano-chemical pathways to H20 and CO2 splitting. Appl. Phys. Lett.. Vol. 99, pp. 154105.
    • Dahal, H., Muniz, R., Haas, S., Graf, M., Balatsky, A. (2011). Visualization of nano-plasmons in graphene. Phil. Mag.. Vol. 10
    • Albash, T., Haas, S. (2011). Quantum liquids move to a higher dimension. Physics. Vol. 4, pp. 62.
    • Chancellor, N., Haas, S. (2011). Propagation of disturbances in degenerate quantum systems. Phys. Rev. B. (84), pp. 035130.
    • Chang, Y., Haas, S. (2011). Defect Induced Resonances and Magnetic Patterns in Graphene. Phys. Rev. B. Vol. 83, pp. 085406.
    • Das, A., Garnerone, S., Haas, S. (2011). Entanglement and its evolution following a quench in the presence of an energy current. PHYSICAL REVIEW A. Vol. 84 (5)
    • Chang, Y. C., Haas, S. (2011). Defect-induced resonances and magnetic patterns in graphene. PHYSICAL REVIEW B. Vol. 83 (8)
    • Bray-Ali, N., Haas, S. (2010). How to turn a topological insulator into a superconductor. Physics. pp. 11.
    • Yu, R., Haas, S., Roscilde, T. (2010). Universal phase diagram of disordered bosons from a doped quantum magnet. Euro. Phys. Lett.. Vol. 89, pp. 10009.
    • Garnerone, S., de Oliveira, T., Haas, S., Zanardi, P. (2010). Statistical properties of random matrix product states. Phys. Rev. A. Vol. 82, pp. 052312.
    • Yu, R., Nohadani, O., Haas, S., Roscilde, T. (2010). Magnetic Bose-glass phases of coupled antiferromagnetic dimers with site dilution. Phys. Rev. B. Vol. 82, pp. 134437.
    • Diez, M., Chancellor, N., Haas, S., Campo Venuti, L., Zanardi, P. (2010). Local quenches in frustrated quantum spin chains: Global versus subsystem equili- bration. Phys. Rev. A. Vol. 82, pp. 032113.
    • Muniz, R., Dahal, H., Balatsky, A., Haas, S. (2010). Impurity-assisted nanoscale localization of plasmonic excitations in graphene. Phys. Rev. B. Vol. 82, pp. 081411.
    • Zhang, W., Haas, S. (2010). Phase diagram of magnetization reversal processes in nanorings. Phys. Rev. B. Vol. 81, pp. 064433.
    • Diez, M., Chancellor, N., Haas, S., Venuti, L. C., Zanardi, P. (2010). Local quenches in frustrated quantum spin chains: Global versus subsystem equilibration. PHYSICAL REVIEW A. Vol. 82 (3)
    • Yu, R., Nohadani, O., Haas, S., Roscilde, T. (2010). Magnetic Bose glass phases of coupled antiferromagnetic dimers with site dilution. PHYSICAL REVIEW B. Vol. 82 (13)
    • Tsomokos, D., Hamma, A., Zhang, W., Fazio, R., Haas, S. (2009). Topological order following a quantum quench. Phys. Rev. A. Vol. 80, pp. 060302.
    • Bray-Ali, N., Ding, L., Haas, S. (2009). Topological order in paired states of fermions in two dimensions with breaking of parity and time-reversal symmetries. Phys. Rev. B. Vol. 80, pp. 060302.
    • Rigol, M., Shastry, S., Haas, S. (2009). Fidelity and superconductivity in two-dimensional t-J models. Phys. Rev. B. Vol. 80, pp. 094529.
    • Yu, R., Roscilde, T., Haas, S. (2009). Revealing Novel Quantum Phases in Quantum Antiferromagnets on Random Lattices. Condensed Matter Physics. Vol. 12, pp. 519.
    • Zhang, W., Haas, S. (2009). Adaptation and Performance of the Cartesian Coordinates Fast Multipole Method for Nanomagnetic Simulations. Journal of Magnetism and Magnetic Materials. Vol. 321, pp. 3687.
    • Muniz, R., Haas, S., Levi, A., Grigorenko, I. (2009). Plasmonic excitations in tight-binding nanostructures. Phys. Rev. B. Vol. 80, pp. 045413.
    • Jacobson, N., Garnerone, S., Haas, S., Zanardi, P. (2009). Scaling of the fidelity susceptibility in a disordered quantum spin chain. Phys. Rev. B. Vol. 79, pp. 184427.
    • Oliveira, B., Haas, S. (2009). Electron-phonon bound states and impurity band formation in quantum wells. Phys. Rev. B. Vol. 79, pp. 155102.
    • Yu, R., Trinh, K., Moreo, A., Daghofer, M., Riera, J., Haas, S., Dagotto, E. (2009). Magnetic and metallic state at intermediate Hubbard U coupling in multiorbital models for undoped iron pnictides. Phys. Rev. B. Vol. 79, pp. 104510.
    • Garnerone, S., Abasto, D., Haas, S., Zanardi, P. (2009). Fidelity in topological quantum phases of matter. Phys. Rev. A. Vol. 79, pp. 032302.
    • Rigol, M., Shastry, S., Haas, S. (2009). Effects of Strong Correlations and Disorder in d-Wave Superconductors. Phys. Rev. B. Vol. 79, pp. 052502.
    • Roy-Choudry, K., Haas, S., Levi, A. (2009). Quantum fluctuations in small lasers. Phys. Rev. Lett.. Vol. 102, pp. 053902.
    • Garnerone, S., Jacobson, N., Haas, S., Zanardi, P. (2009). Fidelity Approach to the Disordered Quantum XY Model. Phys. Rev. Lett.. Vol. 102, pp. 057205.
    • Cassidy, A., Grigorenko, I., Haas, S. (2008). Formation of collective excitations in quasi-one-dimensional metallic nanostructures: size and density dependence. Physical Review B. Vol. 77, pp. 245404.
    • Ding, L., Bray-Ali, N., Yu, R., Haas, S. (2008). Subarea law of entanglement in nodal fermionic systems. Physical Review Letters. Vol. 100, pp. 215701.
    • Hamma, A., Zhang, W., Haas, S., Lidar, D. (2008). Entanglement, fidelity, and topological entropy in a quantum phase transition to topological order. Physical Review B. Vol. 77, pp. 155111.
    • Zhang, W., Singh, R., Bray-Ali, N., Haas, S. (2008). Scaling Analysis and Application: Phase Diagram of Magnetic Nanorings and Elliptical Particles. Physical Review B. Vol. 77, pp. 144428.
    • Yu, R., Saleur, H., Haas, S. (2008). Entanglement entropy in the two-dimensional random transverse field Ising model. Physical Review B. Vol. 77, pp. 140402.
    • Grigorenko, I., Haas, S., Balatsky, A. (2008). Optimal control of electromagnetic field using metallic nanoclusters. New Journal Of Physics. Vol. 10, pp. 043017.
    • Yu, R., Roscilde, T., Haas, S. (2008). Field induced disordered-local-moment phase in site-diluted spin-gap antiferromagnets. New Journal of Physics. Vol. 10, pp. 013034.
    • Zhang, W., Singh, R., Bray-Ali, N., Haas, S. (2008). Scaling analysis and application: Phase diagram of magnetic nanorings and elliptical nanoparticles. PHYSICAL REVIEW B. Vol. 77 (14)
    • Parker, D., Haas, S. (2007). T1^(-1) peak near Tc in unconventional Bardeen-Cooper-Schrieffer superconductors. Phys. Rev. B. Vol. 75, pp. 052501.
    • Sengupta, P., Haas, S., Raghavan, A. (2007). Disorder-enhanced phase coherence in trapped bosons on optical lattices. New J. Physics. Vol. 9, pp. 103.
    • Roscilde, T., Haas, S. (2007). Mott glass in site-diluted S=1 antiferromagnets with single-ion anisotropy. Phys. Rev. Lett.. Vol. 99, pp. 047205.
    • Sengupta, P., Haas, S. (2007). Quantum glass phases in the disordered Bose-Hubbard model. Phys. Rev. Lett.. Vol. 99, pp. 050403.
    • Parker, D., Haas, S., Balatsky, A. (2007). Generalized cuprate gap symmetry and higher d-wave harmonics: Effects of correlation length, doping, temperature, and impurity scattering. Phys. Rev. B. Vol. 76, pp. 104503.
    • Haas, S., Maki, K., Dahm, T., Thalmeier, P. (2007). Anatomy of Gossamer superconductivity. Curr. Appl. Phys.. Vol. 7, pp. 64.
    • Parker, D., Haas, S. (2007). T-1(-1) peak near T-c in unconventional Bardeen-Cooper-Schrieffer superconductors. PHYSICAL REVIEW B. Vol. 75 (5)
    • Parker, D., Haas, S. (2007). T-1(-1) peak near T-c in unconventional Bardeen-Cooper-Schrieffer superconductors (vol 75, art no 052501 2007). PHYSICAL REVIEW B. Vol. 76 (14)
    • Won, H., Haas, S., Maki, K. (2007). Bottom-up approach to high-temperature superconductivity. PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS. Vol. 244 (7), pp. 2407-2414.
    • Grigorenko, I., Haas, S., Levi, A. F. (2006). Electromagnetic response of broken-symmetry nanoscale clusters. Physical review letters. Vol. 97 (3), pp. 036806. PubMed Web Address
    • Grigorenko, I., Haas, S. W., Levi, A. (2006). Electromagnetic response of broken-symmetry nano-scale clusters. Physical Review Letters/American Physical Society. Vol. 97, pp. 036906 (2006).
    • Li, W., Ding, L., Yu, R., Roscilde, T., Haas, S. W. (2006). Scaling Behavior of Entanglement in Two- and Three-Dimensional Free Fermions. Physical Review B/American Physical Society. Vol. 74, pp. 073103.
    • Won, H., Haas, S. W., Maki, K., Parker, D., Dora, B., Virosztek, A. (2006). Gossamer superconductivity, new paradigm?. Phys. Stat. Sol. (b). Vol. 243, pp. 37.
    • Parker, D., Haas, S. W., Maki, K. (2006). BCS theory of unconventional superconductivity in PrOs_4Sb_12. Physica B/Elsevier Science. Vol. 378-380, pp. 902.
    • Maki, K., Haas, S. W., Dora, B., Virosztek, A. (2006). New world of Gossamer superconductivity. Phys. Stat. Sol. (c)/Wiley. Vol. 3, pp. 3156.
    • Roscilde, T., Haas, S. W. (2006). Bose-Einstein Condensation vs. Localization of Bosonic Quasiparticles in Disordered Weakly-Coupled Dimer Antiferromagnets. J. Phys. B: At. Mol. Opt. Phys./Institute of Physics. Vol. 39, pp. 153.
    • Yu, R., Roscilde, T., Haas, S. (2006). Quantum disorder and Griffiths singularities in bond-diluted two-dimensional Heisenberg antiferromagnets. Physical Review B/American Physical Society. Vol. 73, pp. 064406.
    • Schmid, P., Haas, S., Levi, A. (2006). Synthesis of Electron Transmission in Nanoscale Semiconductor Devices. Appl. Phys. Lett.. Vol. 88, pp. 013502.
    • Li, W., Ding, L., Yu, R., Roscilde, T., Haas, S. (2006). Scaling Behavior of Entanglement in Two- and Three-Dimensional Free Fermions. Phys. Rev. B. Vol. 74, pp. 073103.
    • Roscilde, T., Haas, S. (2006). Bose-Einstein condensation versus localization of bosonic quasiparticles in disordered weakly-coupled dimer antiferromagnets. JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS. Vol. 39 (10), pp. S153-S162.
    • Li, W., Ding, L., Yu, R., Roscilde, T., Haas, S. (2006). Scaling behavior of entanglement in two- and three-dimensional free-fermion systems. PHYSICAL REVIEW B. Vol. 74 (7)
    • Roscilde, T., Yu, R., Haas, S. (2006). Quantum-disordered antiferromagnets on random lattices. Low Temperature Physics, Pts A and B. Vol. 850, pp. 1073-1074.
    • Maki, K., Won, H., Parker, D., Haas, S. W., Izawa, K., Matsuda, Y. (2005). Triplet superconductivity in PrOs_4Sb_12. Physica B/Elsevier Science. Vol. 359, pp. 527-529.
    • Nohadani, O., Haas, S. W. (2005). Bose-Glass Phases in Disordered Quantum Magnets. Physical Review Letters/American Physical Society. Vol. 95, pp. 227201.
    • Roscilde, T., Haas, S. W. (2005). Quantum localization in bilayer Heisenberg antiferromagnets with site dilution. Physical Review Letters/American Physical Society. Vol. 95, pp. 207206.
    • Yu, R., Roscilde, T., Haas, S. W. (2005). Quantum percolation in two-dimensional antiferromagnets. Physical Review Letters/American Physical Society. Vol. 94, pp. 197204.
    • Roscilde, T., Verrucchi, P., Fubini, A., Haas, S. W., Tognetti, V. (2005). Entanglement and factorized ground states in two-dimensional quantum antiferromagnets. Physical Review Letters/American Physical Society. Vol. 94, pp. 147208.
    • Thalken, J., Haas, S. W., Levi, A. (2005). Synthesis for semiconductor device design. Journal of Applied Physics/American Institute of Physics. Vol. 98, pp. 044508.
    • Nohadani, O., Haas, S. W. (2005). Quantum Phase Transitions in Coupled Dimer Compounds. Physical Review B/American Physical Society. Vol. 72, pp. 024440.
    • Won, H., Haas, S. W., Parker, D., Maki, K. (2005). High-T_c Cuprate Superconductivity in a Nutshell. Phys. Stat. Sol. (b). Vol. 242, pp. 363.
    • Roscilde, T., Verrucchi, P., Fubini, A., Haas, S. W., Tognetti, V. (2004). Studying quantum spin systems through entanglement estimators. Physical Review Letters/American Physical Society. Vol. 93, pp. 167203.
    • Roscilde, T., Feiguin, A., Chernyshev, A., Liu, S., Haas, S. W. (2004). Anisotropy-Induced Ordering in the Quantum J_1-J_2 Antiferromagnet. Physical Review Letters/American Physical Society. Vol. 93, pp. 017203.
    • Gheorma, I., Haas, S. W., Levi, A. (2004). Aperiodic Nano-Photonic Design. Journal of Applied Physics/American Institute of Physics. Vol. 95, pp. 1420.
    • Nohadani, O., Normand, B., Haas, S. W. (2004). Universal scaling at field-induced magnetic phase transitions. Physical Review B/American Physical Society. Vol. 69, pp. 220402.
    • Thalken, J., Chen, Y., Levi, A., Haas, S. W. (2004). Adaptive Quantum Design of Atomic Clusters. Physical Review B/American Physical Society. Vol. 69, pp. 195410.
    • Won, H., Maki, K., Haas, S. W., Oelscher, N., Weickert, F., Gegenwart, P. (2004). Upper Critical Field and Fulde-Ferrell-Larkin-Ovchinnikov State in CeCoIn_5. Physical Review B/American Physical Society. Vol. 69, pp. 180504.
    • Maki, K., Haas, S. W., Parker, D., Won, H., Izawa, K., Matsuda, Y. (2004). Triplet superconductivity in the skutterudite PrOs_4Sb_{12}. Europhysics Letters/EDP Sciences. Vol. 68, pp. 720.
    • Won, H., Parker, D., Haas, S. W., Maki, K. (2004). Aspects of Nodal Superconductivity. Curr. Appl. Phys.. Vol. 4, pp. 523.
    • Thalken, J., Li, W., Haas, S. W., Levi, A. (2004). Adaptive Design of Excitonic Absorption in Broken-Symmetry Quantum Wells. Applied Physics Letters/American Institute of Physics. Vol. 85, pp. 121.
    • Maki, K., Won, H., Haas, S. W. (2003). Quasiparticle spectrum of the hybrid s+g-wave superconductors YNi_2B_2C and LuNi_2B_2C. Physical Review B/American Physical Society. Vol. 69, pp. 012502.
    • Haas, S., Maki, K. (2003). Reply to Comment on “Theory of c-axis Josephson tunneling in d_{x^2-y^2}-wave superconductors”. Phys. Rev. B. Vol. 68, pp. 226502.
    • Haas, S., Chen, Y., Rong, Y., Li, W., Nohadani, O., Levi, A. (2003). Adaptive Design of Nano-Scale Dielectric Structures for Photonics. J. Appl. Phys.. Vol. 94, pp. 6065.
    • Haas, S., Wessel, S., Jagannathan, A. (2003). Quantum Antiferromagnetism in Quasicrystals. Phys. Rev. Lett.. Vol. 90, pp. 177205.
    • Haas, S., Maki, K. (2003). Theory of c-axis Josephson tunneling in d-wave superconductors. Phys. Rev. B. Vol. 67, pp. 020510(R).
    • Haas, S., Parker, D., Maki, K. (2003). Impurity Bound States in the Pseudogap Phase of High-T_c Cuprates. Acta Phys. Pol.. Vol. B34, pp. 583.
    • Haas, S. W. (2002). Redistribution of Spectral Weight in Spin-1/2-Doped Haldane Chains. S. Wessel and S. Haas, to be published in Phys. Rev. B (2002).
    • Haas, S. W. (2002). Anisotropic s-wave superconductivity in MgB2. S. Haas and K. Maki, Rev. B 65, 020502 (R) (2002).
    • Haas, S., Maki, K., Gerami, R. (2002). Effects of Andreev Scattering on the Tunneling Conductance in Superconducting MgB_2. J. Phys. Chem. Solids. Vol. 63, pp. 1501.
    • Haas, S. W. (2001). Field-Induced Magnetic Order in Quantum Spin Liquids. S. Wessel, M. Olshanii, and S. Haas, Phys. Rev. Lett. 87, 206407 (2001).
    • Haas, S. W. (2001). Phase Diagram and Thermodynamic Properties of the Square Lattice of Antiferromagnetic Spin-1/2 Triangles in La4Cu3MoO12. S. Wessel and S. Haas, Phys. Rev. B 63, 140403 (2001).
    • Haas, S., Wessel, W., Normand, B., Sigrist, M. (2001). Order by Disorder from Non-Magnetic Impurities in a Two-Dimensional Quantum Spin Liquid. Phys. Rev. Lett.. Vol. 86, pp. 1086.
    • Haas, S., Yu, W. (2001). Dynamical Properties of Spin-Orbital Chains in a Magnetic Field. Phys. Rev. B. Vol. 63, pp. 24423.
    • Haas, S., Maki, K. (2000). Impurity Bound States and Symmetry of the Superconducting Order Parameter in Sr_2RuO_4. Phys. Rev. B. Vol. 62, pp. R11969.
    • Haas, S., Maki, K. (2000). Quasi-Particle Bound States around Impurities in d_{x^2-y^2}-Wave Superconductors. Phys. Rev. Lett.. Vol. 85, pp. 2172.
    • Haas, S., Maki, K. (2000). Paramagnetic Reentrance Effect in NS Proximity Cylinders. Phys. Lett. A. Vol. 272, pp. 271.
    • Haas, S., Wessel, S. (2000). Magnetic Field Induced Ordering in Quasi-One-Dimenstional Quantum Magnets. Eur. Phys. J. B. Vol. 16, pp. 393.
    • Haas, S., Yu, W. (2000). Excitation Spectra of Structurally Dimerized and Spin-Peierls Chains in a Magnetic Field. Phys. Rev. B. Vol. 62, pp. 344.
    • Haas, S., Wessel, S. (2000). Three-Dimensional Ordering in a Weakly Coupled Antiferromagnetic Ladders and Chains. Phys. Rev. B. Vol. 62, pp. 316.
    • Haas, S., Wessel, S. (2000). Excitation Spectra and Thermodynamical Response of Segmented Heisenberg Spin Chains. Phys. Rev. B. Vol. 61, pp. 15262.
    • Haas, S., Gagliardini, P., Rice, T. (1998). Generalization of the Luttinger Theorem for Fermionic Ladder Systems. Phys. Rev. B. Vol. 58, pp. 9603.
    • Haas, S., Duffy, D., Kim, E. (1998). Evolution of the Low-Energy Excitation Spectrum from the Pure Hubbard Ladder to the SO(5) Ladder: A Numerical Study. Phys. Rev. B. Vol. 58, pp. 5932.
    • Haas, S. (1998). Spectral Analysis of Correlated One-Dimensional Systems with Impurities. Phys. Rev. Lett.. Vol. 80, pp. 4052.
    • Haas, S., Rice, T., Sigrist, M., Zhang, F. (1997). Lightly Doped t-J Three-Leg Ladders –an Analog for the Underdoped Cuprates. Phys. Rev. B. (14655)
    • Haas, S., Augier, D., Poilblanc, D., Delia, A., Dagotto, E. (1997). Dynamical Properties of the Spin–Peierls Compound alpha-NaV_2O_5. Phys. Rev. B. Vol. 56, pp. R5732.
    • Haas, S., Balatsky, A., Sigrist, M., Rice, T. (1997). Extended Gapless Regions in Disordered d_{x^2-y^2}-Wave Superconductors. Phys. Rev. B. Vol. 56, pp. 5108.
    • Haas, S., Duffy, D., Nazarenko, A., Moreo, A., Riera, J., Dagotto, E. (1997). Hole Doping Evolution of the Quasiparticle Band in Models of Strongly Correlated Electrons for the High-T_c Cuprates. Phys. Rev. B. Vol. 56, pp. 5597.
    • Haas, S., Favand, J., Penc, K., Mila, F., Dagotto, E. (1997). Spectral Functions of One-Dimensional Models of Correlated Electrons. Phys. Rev. B. Vol. 55, pp. R4859.
    • Haas, S., Frischmuth, B., Sierra, G., Rice, T. (1997). Low-Energy Properties of Antifgerromagnetic Spin-1/2 Heisenberg Ladders with an Odd Number of Legs. Phys. Rev. B. Vol. 55, pp. R3340.
    • Haas, S., Zhang, F., Mila, F., Rice, T. (1996). Spin and Charge Texture around Impurities in the CuO_2 Planes. Phys. Rev. Lett. Vol. 77, pp. 3021.
    • Haas, S., Dagotto, E. (1996). Photoemission Spectra in t-J Ladders with Two Legs. Phys. Rev. B. Vol. 54, pp. R3718.
    • Haas, S., Dagotto, E. (1995). Predictions for Neutron Scattering and Photoemission Experiments on CuGeO_3. Phys. Rev. B. Vol. 52, pp. R14396.
    • Haas, S., Nori, F., Merlin, R., Sandvik, A., Dagotto, E. (1995). Magnetic Raman Scattering in Two-Dimensional Spin-1/2 Heisenberg Antiferromagnets: Spectral Shape Anomaly and Magnetostrictive Effects. Phys. Rev. Lett.. Vol. 75, pp. 553.
    • Haas, S., Moreo, A., Dagotto, E. (1995). Antiferromagnetically Induced Photoemission Band in the Cuprates. Phys. Rev. Lett. Vol. 74, pp. 4281.
    • Haas, S., Moreo, A., Dagotto, E. (1995). Quasiparticle Dispersion of the t-J and Hubbard Models. Phys. Rev. B. Vol. 51, pp. 12045.
    • Haas, S., Nazarenko, A., Vos, K., Dagotto, E., Gooding, R. (1995). Photoemission Spectra of Sr_2CuO_2Cl_2: A Theoretical Analysis. Phys. Rev. B. Vol. 51, pp. 8676.
    • Haas, S. (1995). Doping Dependence of the Fermi Surface in the t-J Model. Phys. Rev. B. Vol. 51, pp. 11748.
    • Haas, S., Dagotto, E., Nazarenko, A., Riera, J. (1995). Liaison between Superconductivity and Phase Separation. Phys. Rev. B. Vol. 51, pp. 5989.
    • Haas, S., Riera, J., Dagotto, E. (1993). Random Exchange Disorder in the Spin-1/2 XXZ Chain. Phys. Rev. B. Vol. 48, pp. 3281.
    • Haas, S., Riera, J., Dagotto, E. (1993). Dynamical Properties of Antiferromagnetic Heisenberg Spin Chains. Phys. Rev. B. Vol. 48, pp. 13174.
    • Haas, S. (1992). Isolated Ferromagnetic Bonds in the Two-Dimensional Spin-1/2 Heisenberg Antiferromagnet. Phys. Rev. B. Vol. 46, pp. 3135.

    Proceedings

    • Won, H., Haas, S. W., Parker, D., Telang, S., Vanyolos, A., Maki, K. (2005). BCS Theory of Nodal Superconductors. pp. 3-43. AIP Conference Proceedings.
    • Maki, K., Haas, S. W., Parker, D., Won, H. (2005). Perspectives on Nodal Superconductors. pp. 1. Chinese Journal of Physics.
    • Won, H., Haas, S. W., Maki, K. (2004). Upper Critical Field and Fulde-Ferrell-Larkin-Ovchinnikov State in CeCoIn_5. pp. 191. Journal of Magnetism and Magnetic Matter.
    • Normand, B., Matsumoto, M., Nohadani, O., Rice, T., Sigrist, M., Haas, S. W. (2004). Pressure- and field-induced magnetic quantum phase transition in TlCuCl_3. pp. 583. Acta Phys. Pol. B.
    • Alexander von Humboldt Fellowship Recipient, 2013-2014
    • USC Associates Award For Excellence In Teaching, 2009-2010
    • NIH/NSF Career Development Award, 2000 – 2005
    • USC or School/Dept Award for Teaching, USC General Education Award, 2001
    • USC Raubenheimer Outstanding Junior Faculty Award, 2001
    • Fulbright Award, Scholar, 1990 – 1991

  • Administrative Appointments

    • Chair, 08/16/2024 – 08/15/2027
    • Chair, 08/16/2021 – 08/15/2024
    • Chair, 08/16/2018 – 08/15/2021
    • Chair, 08/16/2015 – 08/15/2018
    • Vice Dean for Research, 01/01/2011 – 09/30/2012

  • Editorships and Editorial Boards

    • Associate Editor, Journal of Superconductivity and Novel Magnetism, 2018 –

    Professional Memberships

    • American Association for the Advancement of Science, 1998 – 2010
    • American Association of Physics Teachers, 1998 – 2010
    • American Physical Society, 1992 – 2010

    Reviewer for Publications

    • Physical Review Letters, Physical Review B, Journal of Physics, National Science Foundation, Departm, Physical Review Letters, Physical Review B, Journal of Physics, National Science Foundation, Department of Energy, Canadian Science Foundation, 2004 –
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