Dr. Jinwu Ye

Assistant Professor of Physics (at the Physics Department of Penn State University )

Office: 125 Davey Lab., Penn State University, University Park, PA 16802, U.S.A.
Phone: +1 (814) 863-5345
E-mail: jye@phys.psu.edu

You can have a look at my photos

I am a faculty member of condensed matter theory group.

 

Research Interests

Brief summary: Quantum phase transitions, High temperature superconductivity, Quantum Hall effect, Non-relativistic Quantum field theory, Quantum Antiferromagnets, Quantm spin glass, quantum optics and closed string field theory.

My most recent interests are: (1) quantum phase transitions in Bi-layer quantum Hall systems (2) Phases and phase transitions in extended boson Hubbard models on various kinds of lattices (3) Inter-disciplinary direction involving quantum phase transitions and quantum optics: Photoluminescence from quantum phases of excitons in electron-hole semi-conductor bilayers (EHBL). (4) Inter-disciplinary direction involving strongly correlated electrons and string theory: Closed string field theory approach to quantum phase transitions on various kinds of three dimensional lattices.

Longer description: My interests are in the theory of condensed matter physics, especially in strongly correlated electron systems. The behavior of a single electron may be easily understood by quantum mechanics, but the cooperative behaviors of many strongly correlated electrons are very intricate and complex. It is well known that water has three different states ( or phases ) as solid, liquid and gas at different temperatures. There also exist lattice oscillations in solid, ripples in liquid and sound waves in gas. Lattice oscillations, ripples and sound waves are excitations above these states respectively. Strongly correlated electron systems may enter into novel states at very low temperatures which are close to the absolute zero temperature, there may also exist some exotic excitations above the novel states of matter. With the ever increasing advance of experimental techniques, these systems are discovered to show novel and highly interesting behaviors at low temperature. I am trying to understand the underlying mechanisms and identify the possible new kinds of states of matter hidden behind these observed novel phenomena. Although the classical mechanics works very well to describe the three different states of water, their excitations and the classical phase transitions between the three states, it breaks down at very low temperature, quantum mechanics manifests its dominance at low temperature. Due to the strong correlations between the electrons, the conventional weak-coupling perturbative calculations around non-interacting metallic state does not apply, the systems may regroup themselves and enter into completely new states of matter which may be dramatically different from the conventional metallic state. I am trying to develop fully quantum mechanical and strong-coupling approaches to understand different novel ground states, exotic excitations above them and the quantum phase transitions between these states. Any correct understandings should be able to explain the experimental discoveries and make new predictions to be tested by experiments. Some of the specific examples are: High Temperature Superconductivity, Superfluidity and Quantum Hall Effects.

Recent Publications

  1. Jinwu Ye, Quantum phases and phase transitions of interacting bosons in a Kagome lattice, arXiv:0804.3429 .
  2. T. Shi, Jinwu Ye, C. P. Sun, Angle resolved power spectrum, squeezing spectrum and photon statistics from exciton condensate in Electron-Hole Bilayer Systems arXiv:0802.1065 .
  3. Jinwu Ye, Quantum phases, transitions, metastable supersolid of excitons and its internal photon detection in electron-hole bilayer systems, arXiv:0712.0437.
  4. Jinwu Ye, Superfluid, solid, supersolid and quantum phase transitions on bipartite lattices and its applications on ultra-cold atoms on optical lattices, adatom adsorption on substrates and high temperature superconductors arXiv:0712.0251.
  5. Longhua Jiang and Jinwu Ye, Lattice structures of Larkin-Ovchinnikov-Fulde - Ferrell (LOFF) state, Phys. Rev. B 76, 184104 (2007)
  6. Jinwu Ye, Elementary excitations in a supersolid, cond-mat/0705.0770. To appear in Europhysics Letters.
  7. Jing Yu Gan, Yu Chuan Wen, Jinwu Ye, Tao Li, Shi-Jie Yang, Yue Yu, The Extended Bose Hubbard Model on the Two Dimensional Honeycomb Lattice Phys. Rev. B 75, 214509 (2007)
  8. Jinwu Ye, Supersolids and Solids to supersolids transitions in frustrated lattices. cond-mat/0612009.
  9. Longhua Jiang and Jinwu Ye, Ground state, quasihole, a pair of quasihole wavefunctions and instability in Bi-layer Quantum Hall systems, Phys. Rev. B 74, 245311 (2006)
  10. Jinwu Ye and Longhua Jiang, Excitonic superfluid to pseudo-spin density wave transition in bilayer quantum Hall systems. Phys. Rev. Lett. 98, 236802 (2007) .
  11. Jinwu Ye, Ginsburg-Landau theory of supersolid, Phys. Rev. Lett. 97, 125302 (2006)
  12. Jinwu Ye, Ginsburg-Landau theory of solid and supersolid and their applications to helium 4 system, cond-mat/0603269.
  13. Longhua Jiang and Jinwu Ye, The Hofstadter bands and their bandwidths in square, honeycomb, triangular, Kagome and Dice lattices at magnetic $ f=1/q $ flux quantum per plaquette. J. Phys, Condensed Matter. 18 (2006) 6907-6922 .
  14. Jinwu Ye, Solid to supersolid transitions in bipartite lattices model, cond-mat/0503113. Submitted to Phys.Rev. Lett.
  15. Gun Sang Jeon and Jinwu Ye, Investigation of trial wavefunction approach to bilayer Quan tum Hall systems, Phys. Rev. B 71, 035348 (2005) (10 pages) .
  16. Jinwu Ye, Fractional charges and quantum phase transitions in imbalanced bilayer quantum Hall systems, Phys. Rev. Lett. 97, 236803 (2006) .
  17. Jinwu Ye, Broken symmetry, gapless modes and topological excitations in Trilayer Quantum Hall systems. Phys. Rev. B 71, 125314 (2005) (9 pages) . .
  18. Jinwu Ye, Mutual Composite Fermion and Composte Boson approaches to balanced and im-balanced bilayer quantum Hall systems: an electronic analogy of Helium 4 system, cond-mat/0310512. Published online in Annals of Physics. To appear in hard copy in Annals of Physics
  19. Jinwu Ye, Gauge-invariant Green function in 3+1 dimensional QED and 2+1 dimenional Chern-Simon Theory, Journal of Physics: Condensed Matter, volume 16, issue 25, pages 4465 - 4476 (2004).
  20. Jinwu Ye, On Gauge-invariant Green function in 2+1 dimensional QED, Phys. Rev. B 67, 115104 (2003).
  21. Jinwu Ye, Quantum fluctuation generated vortices, dual singular gauge transformation and zero temperature transition from d-wave superconductor to underdoped regime, Phys. Rev. B 65, 214505 (2002).
  22. Jinwu Ye, Thermally generated vortices, gauge invariance and electron spectral function in the pseudo-gap regime. Phys. Rev. Lett. 87, 227003 (2001)
  23. Jinwu Ye, Random Magnetic Field and Quasiparticle Transport in the Mixed State of High-Tc  Cuprates.
           Phys. Rev. Lett. 86, 316-319 (2001)

I taught the following courses

(1) Undergraduate   Mechanics II, 461 (syllabus)
(2) Graduate   Quantum Theory of Solids I , 512 (syllabus)
(3) Graduate  Quamtum Theory of Solids II ( Many Body Physics ), 513 (syllabus)
(4) Graduate  Critical Phenomena and Field Theory, 518 (syllabus)
(5) Graduate  Advanced Quantum Mechanics 562, (syllabus)


Jinwu Ye, jye@phys.psu.edu , 11 June 2002.