Condensed Matter Theory Group

Department of Physics, Tunghai University

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Overview

The Condensed Matter Theory (CMT) Group at Tunghai University is the essential group in researching theoretical condensed matter physics with both analytical and numerical methods. Basically, the targets of investigation are various lattice models.

Since several main algorithms in lattice systems are emploied and the computational resources are abundant, numerical study expecially has become the feature of the group. The members are proficient in Variational and Quantum Monte Carlo simulations, Exact Diagonalization, and Density Matrix Renormalization Group. On the other hand, almost 200 high performance PCs are built into lots of PC-Clusters for parallel computing.

The research interests of the professors cover diverse subareas. A regular seminar takes place on each Thursday on the topics of high temperature superconductivity, quantum Hall effect, strongly correlated systems, ultra-cold atoms, soft condensed matters, and supersolid phases. Speakers are invited from other universities in Taiwan or from other countries. Moreover, the members of the group also introduce their recent works respectively. Sometimes an internet convention is held with Academic Sinica, National Taiwan University, and National Tsing Hua University; therefore projects are collaborated frequently with other outstanding scholars. The CMT Group is the main theoretical team which plays an important role in the Department of Physics at Tunghai University. Most of theoretical publications of the department of physics were reported by the CMT Group.

Students who desire further study are welcome to contact the faculty directly.

Center for High Performance Computing: Location: ST126, Phone: +886-4-23590121 ext 32107

Theoretical physics discussion group: Your e-mail subscriptions are welcome!

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People

Faculty
• Yung-Chung Chen
professor
• Ph.D in Physics,Sep. 1984 - Jun. 1988, National Tsing Hua Univ. (Taiwan)
• B.S. in ElectroPhysics, Sep. 1980 - Jun. 1984, National Chiao Tung Univ. (Taiwan)
• Prof. Yung-Chung Chen is interested in all aspects about correlation effects in quantum many-body problems. In the past few years, he has been working on the following subjects:
1. Numerical study of the strongly correlated system such as Hubbard Model, t-J Model, and Frustrated Spin Model.
2. Mean field theory and quantum Monte Carlo simulation of the quantum spin systems.
3. Development of new numerical methods for strongy correlated systems, such as the Power-Lanczos Method.
• Min-Fong Yang
professor
• Ph.D in Physics, 1992, National Tsing Hua Univ. (Taiwan)
• B.S. in ElectroPhysics, 1987, National Chiao Tung Univ. (Taiwan)
• Prof. Min-Fong Yang is interested in heavy fermion systems,high-T_c superconductivity, and quantum Hall effect. Recently he also pitched in researching and developing new numerical algorithms such as Tensor Renormalization Group.
• Chi-Tin Shih
professor
• Ph.D in Physics, 1991-1997, National Tsing Hua Univ. (Taiwan)
• B.S. in Physics, 1986-1990, National Tsing Hua Univ. (Taiwan)
• Prof. Chi-Tin Shih's research interests are theory of high-temperature superconductivity, Strongly correlated electron systems, Structure and transport of bio-macromolecules,and High-performance computing and its application on physics. He came off with flying colors in researching extended t-J model,a model describes high-T_c superconductor,and awarded prizes of Academia Sinica and National Center for Theoretical Scinences in 2007. Furthermore, Prof. Chi-Tin Shih applies tight binding model to describe the properties of electronic transport in DNA. The impact of prof. Shih's work is expected longer and wider.
• Yu-Wen Lee
associate professor
• Ph.D in Physics, 1996-2000, National Tsing Hua Univ. (Taiwan)
• M.S. in Physics, 1991-1993, National Taiwan Univ. (Taiwan)
• B.S. in Electrical Engineering, 1987-1991, National Taiwan Univ. (Taiwan)
• Prof. Yu-Wen Lee is intersted in
1. Phases and phase transitions of quantum magnets
2. Transport in low-dimensional systems. Kondo effect and Luttinger liquid
3. Many-body physics of cold atoms
4. Applications of quantum field theory
• Kwai-Kong Ng
assistant professor
• Ph.D in Physics, 1993-1998, University of Cincinnati, Cincinnati OH, USA
• M.S. in Physics, 1991-1993, Hong Kong University of Science and Technology. (Hong Kong)
• B.S. in Physics, 1988-1991, University of Hong Kong. (Hong Kong)
• Prof. Ng's research interest is Strongly correlated quantum many-particle systems, Numerical simulation methods in quantum physics, Quantum phase transitions, and most recently on the numerical study of the supersolid phase in various lattice models.

Postdoctoral Fellowship

Research Personnel:

Research Assistant
• Jianiue Chen
• BSc in Physics, 2007, Tunghai Univ.(Taiwan)

Former Research Assistant
• Jian Jheng Wu
• Yun-Yin Cheng
• M.S. in Physics, 2009, Tunghai Univ.(Taiwan)

Technical Advisor
• Yu-Chin Tzeng
• BSc in Physics, 2005, Tunghai Univ.(Taiwan)
• Military service, 2005 - 2006
• Research Assistant, 2007 - July 2009, Dep. Physics, Tunghai Univ.(Taiwan)
• MSc in Physics, 2011, National Tsing Hua Univ.(Taiwan)
• PC Clusters establishing and managing
• Exact Diagonalization (ED) and Density Matrix Renormalization Group (DMRG) program developement
• Chia-hei Yang
• Adjunct Assistant Professor, 2011-, Physics, Chinese Culture Univ., Taiwan
• Postdoctoral Researcher, 2007-2010, Physics, Tunghai Univ., Taiwan
• Ph.D in Physics, 2007, Univ. of California at Riverside, CA, USA

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Recent Publications ( Since 2005 )

1. Yu-Wen Lee and Min-Fong Yang, Spontaneous dimerization in the spin-1 bilinear-biquadratic Heisenberg model on a honeycomb lattice, arXiv: 1110.0962.
2. Yu-Li Lee and Yu-Wen Lee, The stability of the low-dimensional mixtures of dilute quantum gases, J. Phys. Soc. Jpn. 80, 044003 (2011).
3. A-S Chiang, C-Y Lin, C-C Chuang, H-M Chang, C-H Hsieh, C-W Yeh, C-T Shih, J-J Wu, G-T Wang, Y-C Chen, C-C Wu, G-Y Chen, Y-T Ching, P-C Lee, C-Y Lin, H-H Lin, C-C Wu, H-W Hsu, Y-A Huang, J-Y Chen, H-J Chiang, C-F Lu, R-F Ni, C-Y Yeh, and J-K Hwang, Three-Dimensional Reconstruction of Brain-wide Wiring Networks in Drosophila at Single-Cell Resolution, Current Biology 21, 1 (2011).
4. Yung-Chung Chen, Kwai-Kong Ng, and Min-Fong Yang, Quantum phase transitions in attractive extended Bose-Hubbard Model with three-body constraint, Phys. Rev. B 84, 092503 (2011).
5. Kwai-Kong Ng and Min-Fong Yang, Thermal Phase transitions in attractive extended Bose-Hubbard Model with three-body constraint , Phys. Rev. B 83, 100511(R) (2011).
6. Chi-Tin Shih, Hsuan-Wen Lin, and Ann-Shyn Chiang, Statistical analysis and modeling of the temperature-dependent sleep behavior of drosophila, Computer Physics Communications 182, 195 (2011).
7. Chia-Hei Yang, Ching-Ling Hsu, Nan-Yow Chen, and Chi-Tin Shih, Temporal dynamics of site percolation in nanoparticle assemblies, Computer Physics Communications 182, 71 (2011).
8. Chi-Tin Shih, Yun-Yin Cheng, Stephen A. Wells, Ching-Ling Hsu, and Rudolf A. Romer, Charge transport in cancer-related genes and early carcinogenesis, Computer Physics Communications 182, 36 (2011).
9. Kwai-Kong Ng, Thermal phase transitions of supersolids in the extended Bose-Hubbard model, Phys. Rev. B 82, 184505 (2010).
10. Pochung Chen and Min-Fong Yang, Quantum phase transitions of two-species bosons in square lattice, Phys. Rev. B 82, 180510(R) (2010).
11. Yu-Wen Lee and Min-Fong Yang, Superfluid-Insulator Transitions in Attractive Bose-Hubbard Model with Three-Body Constraint, Phys. Rev. A 81, 061604(R) (2010)
12. Yu-Li Lee and Yu-Wen Lee, Universality and stability for a dilute Bose gas with a Feshbach resonance, Phys. Rev. A 81, 063613 (2010).
13. Kwai-Kong Ng, Yung-Chung Chen, and Yu-Chin Tzeng, Quarter-filled supersolid and solid phases in the extended Bose-Hubbard model, Journal of Physics: Condensed matter 22, 185601, (2010).
14. Kwai-Kong Ng, Phase diagrams of XXZ model on depleted square lattice, Phys. Rev. B 81, 094426 (2010).
15. Pochung Chen, Chen-Yen Lai, and Min-Fong Yang, Field Induced Spin Supersolidity in Frustrated Spin-1/2 Spin-Dimer Models, Phys. Rev. B 81, 020409(R) (2010).
16. Pochung Chen, Chen-Yen Lai, and Min-Fong Yang, Numerical Study of Spin-1/2 XXZ Model on Square Lattice from Tensor Product States, J. Stat. Mech.: Theory Exp. (2009) P10001.
17. Ming-Che Chang and Min-Fong Yang, Optical signature of topological insulators, Phys. Rev. B 80, 113304 (2009).
18. S. Wells, Chi-Tin Shih, and Rudolf A. Romer, Modeling Charge Transport in DNA Using Transfer Matrices with Diagonal Terms, Int. J. Mod. Phys. B. 23, 4138 (2009).
19. Ming-Che Chang and Min-Fong Yang, Magnetization plateau of the classical Ising model on the Shastry-Sutherland lattice: A tensor renormalization-group approach, Phys. Rev. B 79, 104411 (2009).
20. Sergei V. Isakov, Hong-Chi Chien, Jian-Jheng Wu, Yung-Chung Chen, Chung-Hou Chung, Krishnendu Sengupta, Yong Baek Kim, Commensurate lock-in and incommensurate supersolid phases of hardcore bosons on anisotropic triangular lattices , Europhys. Lett. 87, 36002 (2009)
21. Yu-Chin Tzeng, Hsiang-Hsuan Hung, Yung-Chung Chen, Min-Fong Yang, Fidelity approach to Gaussian transitions, Phys. Rev. A 77, 062321 (2008).
22. Kwai-Kong Ng and Yung-Chung Chen, Supersolid phases in the bosonic extended Hubbard model, Phys. Rev. B 77, 052506 (2008).
23. Yu-Wen Lee, Quantum Phase Transitions and the Hidden Order in a Two-Chain Extended Boson Hubbard Model at Half-Odd-Integer Fillings, Phys. Rev. B 77, 064514 (2008).
24. Yu-Chin Tzeng and Min-Fong Yang, Scaling Properties of Fidelity in Spin-1 Anisotropic Model, Phys. Rev. A 77, 012311 (2008).
25. Chi-Tin Shih, Stephan Roche, Rudolf A. Romer, Point Mutations Effects on Charge Transport Properties of the Tumor-Suppressor Gene p53, Phys. Rev. Lett. 100, 018105 (2008).
26. Chi-Tin Shih, Rudolf A. Romer, Stephan Roche, Electric Transport Properties of the p53 Gene and the Effects of Point Mutations, arXiv:0710.1676
27. Chi-Tin Shih, Sequence and Energy Dependence of Electric Transport Properties of DNA - A Tight-Binding Model Study, Chinese Journal of Physics 45, 703 (2007).
28. Min-Fong Yang, Ground-state fidelity in one-dimensional gapless models, Phys. Rev. B 76, 180403(R) (2007).
29. Yu-Wen Lee, Yu-Li Lee, Min-Fong Yang , Low-energy Effective Theory for One-dimensional Lattice Bosons near Integer Filling, Phys. Rev. B 76, 075117 (2007).
30. Yu-Li Lee and Yu-Wen Lee, Low-energy properties of the ferromagnetic metallic phase in manganites: Slave-fermion approach to the quantum double-exchange model, Phys. Rev. B 75, 064411 (2007).
31. Chi-Tin Shih, Jian-Jheng Wu, C. P. Chou, Yung-Chung Chen and T. K. Lee, Variational phase diagram of the electron-doped two-dimensional extended t-J model, Chinese Journal of Physics 45,207 (2007).
32. Kwai-Kong Ng and T.K. Lee, Field-induced supersolid phase in spin dimer XXZ systems, JMMM, 310, 1371 (2007).
33. Ya-Ru Wang, Zhi-Ming Bai, Ji-Qing Qiuz, Yung-Chung Chen, persistent current in two sub-rings coupled by one embedded quantum dot ,Int. J. Mod. Phys. B, 21, 885 (2007).
34. Hsiang-Hsuan Hung, Chang-De Gong, Yung-Chung Chen, Min-Fong Yang, Search for quantum dimer phases and transitions in a frustrated spin ladder , Phys. Rev. B 73, 224433 (2006).
35. Yong-Jun Liu, Yung-Chung Chen, Min-Fong Yang and Chang-De Gong, Magnetic order of the two-dimensional antiferromagnetic 1/4-depleted square lattice, Journal of Physics: Condensed matter 18, 1805, (2006).
36. Min-Fong Yang, Ming-Che Chang, Streda-like formula in spin Hall effect, Phys. Rev. B 73, 073304 (2006).
37. Chi-Tin Shih, Electric transport and coding sequences of DNA molecules, Physica Status Solidi (b) 243, 378. (2006).
38. K. Y. Yang, C. T. Shih, C. P. Chou, S. M. Huang, T. K. Lee, T. Xiang, and F. C. Zhang, Low-energy physical properties of high-T-c superconducting Cu oxides: A comparison between the resonating valence bond and experiments, Phys. Rev. B 73, 224513 (2006).
39. Chi-Tin Shih, Characteristic length scale of electric transport properties of genomes, Phys. Rev. E 74, 010903(R) (2006).
40. Yu-Wen Lee and Yu-Li Lee, Quantum phases of a Feshbach-resonant atomic Bose gas in one dimension, Phys. Rev. A 73, 043606 (2006).
41. Kwai-Kong Ng and T. K. Lee, Supersolid Phase in Spin Dimer XXZ Systems under a Magnetic Field, Phys. Rev. Lett. 97, 127204 (2006).
42. Kwai-Kong Ng and Ting-Kuo Lee, Numerical study of magnetic field induced ordering in BaCuSi₂O₆ and related systems, Phys. Rev. B 73, 014433 (2006).
43. T.K. Lee, Chi-Tin Shih and Chang-Ming Ho, Spectra of the high T_c cuprates understood by the variational studies of the t-J-type models, Journal of Physics and Chemistry of Solids 67,150-153 (2006).
44. Jing-Nuo Wu, Ming-Che Chang, Min-Fong Yang , Persistent spin current in mesoscopic ferrimagnetic spin ring, Phys. Rev. B 72, 172405 (2005).
45. Chi-Tin Shih, Jian-Jheng Wu, Yung-Chung Chen, C-Y. Mou, C.-P. Chou, R.Eder, and T.K. Lee, Antiferromagnetism and superconductivity of the two-dimensional extended t-J model, Low Temperature Physics 31, 757 (2005).
46. Chi-Tin Shih, Yung-Chung Chen, T.K. Lee, d-wave Pairing of the Two-Dimensional Extended t-J Model, Chinese Journal of Physics 43, 543 (2005).
47. Hong-Chi Chien, Yung-Chung Chen, Chi-Tin Shih, Pairing Correlation of the Two-dimensional Hubbard Model, Chinese Journal of Physics 43, 523 (2005).
48. Min-Fong Yang, Reexamination of entanglement and the quantum phase transition, Phys. Rev. A 71, 030302(R) (2005).