Changfeng Chen, Dept of Phys, UNLV
Changfeng Chen

Professor of Physics

Department of Physics
Bigelow Physics Buliding, Room 225
University of Nevada, Las Vegas
Las Vegas, Nevada 89154-4002

Email: chen@physics.unlv.edu
Phone:(702) 895-4230
Fax: (702) 895-0804


Ph.D., Peking University, 1987; Postdoc and Research Associate, Iowa State (1987), UC Berkeley (1988-1989), University of Oregon (1989-1990); at UNLV since 1990.


Teaching:

PHY 180 - Physics for Scientists and Engineers I
PHY 421 - Electricity and Magnetism I
PHY 422 - Electricity and Magnetism II
PHY 412 - Modern Physics I
PHY 467 - Thermodynamics
PHY 707 - Condensed Matter Theory I
PHY 708 - Condensed Matter Theory II
PHY 728 - Application of Group Theory to Quantum Mechanics
PHY 731 - Statistical Physics I
PHY 732 - Statistical Physics II
PHY 777 - Advanced Special Problems
PHY 797 - Master Thesis
PHY 799 - Doctoral Dissertation


Research Group:

Postdocs/Research Associates:

Ki Ho Lee (1994-95); Present Position: Associate Professor, Physics Department, Dankuk University, South Korea.
Rene Fournier (1995-96); Present Position: Associate Professor, Chemistry Department, York University, Canada.
Yimin Gu (1995-96); Present Position: Senior Engineer, Siliconix, California.
Carlos Sanchez-Castro (1996-97).
Eunja Kim (1996-2004).
Weizhong Wang (2000); Present Position: Associate Professor, Huazhong University of Science and Technology, China.
Jizhong Lou (2000-2001); Present Position: Research Scientist, Georgia Institute of Technology.
In-Keun Oh (2002); Present Position: Research Staff, Northern Territory University, Australia.
Jianfeng Gu (2005-2006); Present Position, Associate Professor, Shanghai Jiaotong University, China.
Xuezhi Ke, (2006-2007); Present Position: Associate Professor, East China Normal University, China.
Yufeng Guo, (2007-).
Yi Zhang (2008-).

Graduate Students:

Jianzhong Zheng (1991-96), Ph. D. awarded August 1996; Present Position: Medical Physicist, Radiation Oncology Center of Las Vegas, Nevada
Ningsheng Zhu (1994-2000), Ph. D. awarded August 2000; Present Position: Resident Medical Physicist, University of California, San Francisco
Yang Liu (1995-2000), Ph. D. awarded August 2000
Yi Zhang (2006-2008), visiting graduate student.
Chun Tang (2006-2008), visiting graduate student.

Visiting Faculty and Collaborations:

Enge Wang, Institute of Physics, Chinese Academy of Sciences
Shaojin Qin, Institute of Theoretical Physics, Chinese Academy of Sciences
Xiaoqun Wang, Institute of Theoretical Physics, Chinese Academy of Sciences
Thomas Frauenheim, University of Paderborn, Germany
Xuewen Wang, Florida International University
Yusheng Zhao, Los Alamos National Laboratory
Hong Sun, Shanghai Jiaotong University, China
Wanlin Guo, NUAA, China
Jihui Yang, General Motors

Research Activities:

Computational methods and many-body techniques are employed in the study of novel materials that exhibit properties of great fundamental interest and potential applications. Current research activities include (1) studies of nanomechanical behavior of strong covalent and metallic solids, their nanocomposite forms and nanotubes, (2) nanostructures on semiconductor surfaces and in enclosed cages, (3) hydrogen adsorption on metal-decorated light-element nanostructures, (4) lattice dynamics of solids at high pressure, (5) structural, phonon and electronic properties of advanced thermoelectric materials.

Computational approaches developed and applied to the study of novel materials include a combined first-principles and many-body approach to the study of correlated real materials, density-functional tight-binding total energy calculations, ab initio pseudopotential calculations, density matrix renormalization group method, and first-principles, tight-binding and classical molecular dynamics simulations.

Research projects in the group have been supported by the National Science Foundation, the US Department of Energy, the W. M. Keck Foundation, and the Bigelow Foundation.


Recent Publications

[125] J. Yang, H. Sun, and C. F. Chen, "Is Osmium diboride an ultrahard material?", Journal of American Chemical Society 130, 7200 (2008).

[124] Y. F. Guo, W. L. Guo, and C. F. Chen, "Tuning field-induced energy gap of bilayer graphene via interlayer spacing", Applied Physics Letters 92, 243101 (2008).


This paper ([124]) was featured on the
cover of Applied Physics Letters.
The cover image is shown on the right.

[123] C. Tang, W. L. Guo, and C. F. Chen, "Mechanism for superelongation of carbon nanotubes at high temperatures", Physical Review Letters 100, 175501 (2008).

[122]Y. Zhang, H. Sun, and C. F. Chen, "Influence of carbon content on the strength of cubic BCxN: A first-principles study", Physical Review B 77, 094120 (2008).

[121] X. H. Liu, J. F. Gu, Y. Shen, and C. F. Chen, "Anisotropy in homogenous dislocation nucleation by nanoindentation of single crystal Cu", Scripta Materialia 58, 564 (2008).

[120] Y. F. Guo, W. L. Guo, and C. F. Chen, "Modifying atomic scale friction between two graphene sheets: A molecular force-field study", Physical Review B 76, 155429 (2007).

[119] C. F. Chen and H. Sun, "Comment on 'Superhard Pseudocubic BC2N Superlattices'", Physical Review Letters 99, 159601 (2007).

[118] Y. Zhang, H. Sun, and C. F. Chen, "Ideal tensile and shear strength of beta-C3N4 from first-principles calculations", Physical Review B 76, 144101 (2007).

[117] J. Yang, H. Sun, J. He, Y. Tian, and C. F. Chen, "Diamond-like BC3 as a superhard conductor identified by ideal strength calculations", Journal of Physics: Condensed Matter 19, 346223 (2007).

[116] X. Ke and C. F. Chen, "Thermodynamic functions and pressure-temperature phase diagram of lithium alanates by ab initio calculations", Physical Review B 76, 024112 (2007).

[115] H. Giefers, E. A. Tanis, S. P. Rudin, C. Greeff, X. Ke, C. F. Chen, M. F. Nicol, et al., "Phonon Density of States of Metallic Sn at High Pressure", Physical Review Letters 98, 245505 (2007).

[114] Z. C. Pan, H. Sun, and C. F. Chen, "Colossal shear-strength enhancement of low-density cubic BC_2N by nanoindentation", Physical Review Letters 98, 135505 (2007).

[113] J. T. Wang, D. S. Wang, C. F. Chen, O. Nashima, T. Kanomata, H. Mizuseki, and, Y. Kawazoe, "Vacancy induced structural and magnetic transition in MnCo_{1-x}Ge", Applied Physics Letters 89, 262504 (2006).

[112] J. T. Wang, C. F. Chen, E. G. Wang, D. S. Wang, H. Mizuseki, and Y. Kawazoe, "Two-stage rotation mechanism for group-V precursor dissociation on Si(001)", Physical Review Letters 97, 046103 (2006).

[111] Z. Pan, H. Sun, and C. F. Chen, "Ab initio structural identification of high density cubic BC2N", Physical Review B 73, 214111 (2006).

[110] Z. Pan, H. Sun, and C. F. Chen, "Interlayer stacking and nature of the electronic band gap in graphitic BC2N: First-principles pseudopotential calculations", Physical Review B 73, 193304 (2006).

[109] Y. Zhang, H. Sun, and C. F. Chen, "Structural deformation, strength and instability of cubic BN compared to diamond: A first-principles study", Physical Review B 73, 144115 (2006).

[108] J. Lou, C. F. Chen, X. Wang, "Field-induced midgap excitations in quantum spin chains", Physical Review B 73, 092407 (2006).

[107] Y. Zhang, H. Sun, C. F. Chen, "Strain dependent bonding in solid C3N4: High elastic moduli but low strength", Physical Review B 73, 064109 (2006).

[106] J. Zhao, X. Wang, T. Xiang, Z. Su, L. Yu, J. Lou, and C. F. Chen, "Antiferromagnetic Heisenberg ladders in staggered magnetic field", Physical Review B 73, 012411 (2006).

[105] R. S. Kumar, A. L. Cornelius, E. Kim, Y. Shen, S. Yoneda, C. F. Chen, M. F. Nicol, "Pressure induced structural transition in AgSbTe2", Physical Review B 72, 060101 (2005) [Rapid Communication]

[104] I. K. Oh, J. Singh, E. Kim, and C. F. Chen, "Transferrable tight binding model for Ge", Journal of Noncrystalline Solids 351, 1192 (2005)..

[103]J. Lou, C. F. Chen, J. Zhao, X. Wang, T. Xiang, Z. Su, and L. Yu, "Midgap states in antiferromagnetic Heisenberg chains with a staggered field", Physical Review Letters 94, 217207 (2005).

[102] Z. Pan, H. Sun, and C. F. Chen, "Ab initio pseudopotential study of cubic BC_2N under high pressure", Journal of Physics Condensed Matter 17, 3211 (2005).

[101] C. F. Chen, Topological scaling behavior in antiferromagnetic Heisenberg chains with half-integer spin S>1/2", Physics Letters A 335, 251 (2005).

[100] Y. Zhang, H. Sun, and C. F. Chen, "Atomistic deformation modes in strong covalent solids", Physical Review Letters 94, 145505 (2005).


This paper ([100]) was featured on the
cover of Physical Review Letters.
The cover image is shown on the right.

[99]Y. Zhang, H. Sun, and C. F. Chen, "Superhard cubic BC_2N compared to diamond", Physical Review Letters 93, 195504 (2004).

[98] Z. Pan, H. Sun, and C. F. Chen, "Diverging synthesis routes and distinct properties of cubic BC_2N at high pressure", Physical Review B 70, 174115 (2004).

[97] C. F. Chen, "Multiscale topological structures in quantum spin chains", Physical Review B 70, 092404 (2004).

[96] E. Kim and C. F. Chen, "Calculation of bulk modulus for highly anisotropic materials" Physics Letters A 326, 442 (2004).

[95] E. Kim and C. F. Chen, "First-principles study of phase stability of BN under pressure", Physics Letters A 319, 384 (2003).

[94] C. F. Chen, "Evolution of topological features in short antiferromagnetic Heisenberg chains", Physics Letters A 317, 135 (2003).

[93] J. Lou, S. Qin, and C. F. Chen, "String order in half-integer-spin antiferromagnetic Heisenberg chains", Physical Review Letters 91, 087204 (2003).

[92] J. Lou, S. Qin, T. Xiang, C. F. Chen, G. Tian, and Z. Su, "Transition from band insulator to Mott insulator in one dimension: Critical behavior and phase diagram", Physical Review B 68, 045110 (2003).

[91] S. Qin, J. Lou, L. Sun, and C. F. Chen, "Nonlocal topological order in antiferromagnetic Heisenberg chains", Physical Review Letters 90, 067202 (2003).

[90] E. Kim and C. F. Chen, "Local bonding behavior and domain size relation for vacancy lines on Si(001)" Physical Review B 66, 205418 (2002).

[89] X. Wang, N. Zhu, and C. F. Chen, "Ground-state phase diagram of a spin-1/2 frustrated three-leg antiferromagnetic Heisenberg ladder", Physical Review B 66, 172405 (2002).

[88] C. F. Chen, "Nature of quasiparticles in itinerant correlated electron systems with geometrical frustration", Physics Letters A 303, 81-86 (2002).

[87] E. Kim and C. F. Chen, "Distribution of dimer vacancy lines on Si(001)", Physics Letters A 310, 484-489 (2002).

[86] J. Lou, S. Qin, C. F. Chen, Z. Su, and L. Yu, "Field-induced gap in the spin-1/2 antiferromagnetic Heisenberg chain: A density-matrix renormalization-group study", Physical Review B 65, 064420 (2002).

[85] J. Lou, C. F. Chen, and S. Qin, "Low-energy properties and magnetization plateaus in a 2-leg mixed spin ladder", Physical Review B 64, 144403 (2001).

[84] E. Kim, C. F. Chen, T. Kohler, M. Elstner, and T. Frauenheim, "Theoretical study of body-centered tetragonal phase of carbon nitride", Physical Review B 64, 094107 (2001).

[83] E. Kim and C. F. Chen, "Stability of tetragonal crystalline carbon nitrides: The nitrogen content dependence", Physics Letters A 282, 415-420 (2001).

[82] Y. Liu and C. F. Chen, "Spin and charge response to magnetic frustration in strongly correlated itinerant electron systems", Physical Review B 63, 132402 (2001).

[81]E. Kim, C. F. Chen, T. Kohler, M. Elstner, and T. Frauenheim, "Tetragonal crystalline carbon nitrides: Theoretical predictions", Physical Review Letters 86, 652-655 (2001).

[80]N. Zhu, X. Wang, and C. F. Chen, "Low-energy properties of spin-1/2 two-leg antiferromagnetic Heisenberg ladders with ferromagnetic diagonal coupling", Physical Review B 63, 012401 (2001).

[79] X. Luo, G. Qian, E. G. Wang, and C. F. Chen, " Molecular-dynamics simulation of Al/SiC interface structures", Physical Review B 59, 10125-10131 (1999).

[78] E. Kim, Y. H. Lee, C. F. Chen, and T. Pang, "Vacancies in amouphous silicon: A tight-binding molecular dynamics simulation", Physical Review B 59, 2713-2721 (1999).

[77] E. Kim, C. F. Chen, T. Pang and Y. H. Lee, "Ordering of dimer vacancies on the Si(100) surface", Physical Review B 60, 8680-8685 (1999).

[76] S. Pearson, T. Pang and C. F. Chen, "Critical temperature of trapped hard-sphere Bose gases", Physical Review A 58, 4796-4800 (1998).

[75] S. Pearson, T. Pang and C. F. Chen, "Bose-Einstein condensation in two dimensions: A quantum Monte Carlo study", Physical Review A 58, 4811-4815 (1998).

[74] S. Pearson, T. Pang and C. F. Chen, "Bose-Einstein condensation in one dimensional power-law traps: A path-integral Monte Carlo simulation", Physical Review A 58, 1485-1489 (1998).

[73] L. Y. Zhang, X. Yang and C. F. Chen, "On the characteristics of the pseudogapped metallic state of high-Tc superconductors", International Journal of Modern Physics B 12, 3052-3055 (1998).

[72] X. Luo, G. Qian, W. Fei, E. G. Wang and C. F. Chen, "Systematic study of SiC surface structures by molecular dynamics simulations", Physical Review B 57, 9234-9240 (1998).

[71] R. Fournier, T. Pang and C. F. Chen, "Structural characterization of niobium cluster anions from density functional calculations", Physical Review A 57, 3683-3691 (1998).

[70] E. G. Wang, C. Z. Wang, C. F. Chen and Y. Chen, "Structural characterization of crystalline C-Si-N films", Proceedings of the Symposium of the Materials Research Society 498, 301-306 (1998).

[69] C. F. Chen, E. G. Wang, Y. M. Gu, D. M. Bylander and L. Kleinman, "Unexpected band-gap collapse in quaternary alloys at the group-III-nitride/GaAs interface: GaAlAsN", Physical Review B 57, 3753-3756 (1998).

[68] C. F. Chen and X. W. Wang, "Mapping the electron correlation onto a model Hamiltonian for GaAs(110): A Mott-Hubbard insulator at quarter filling", Journal of Physics Condensed Matter 10, 731-739 (1998).

[67] E. Kim, Y. H. Lee, C. F. Chen and T. Pang, "Structural relaxation of vacancies in amorphous silicon", Proceedings of the Symposium of the Materials Research Society 467, 555-560 (1997).

[66] C. F. Chen, "Combined first-principles and many-body approach to electron correlation problems" (invited review article), Proceedings of the CCAST workshop on computational physics, edited by E. G. Wang and Z. Y. Zhang, (Beijing, June 1997), pp. 1-42.

[65] E. Kim, Y. H. Lee, C. F. Chen, and T. Pang, "Structural and vibrational properties of amorphous SiGe alloys: An ab initio molecular dynamics study", Physical Review B 56, 10200-10207 (1997).

[64] X. W. Wang and C. F. Chen, "Nature of the insulating state in LaH_3", Physical Review B 56, R7049-R7052 (1997).

[63] C. F. Chen and Jianzhong Zheng, "Single-particle excitation spectrum of the Hubbard model with magnetic frustration at finite temperature", Physics Letters A 224, 169-175 (1997).

[62] H. Kietzmann, J. Morenzin, P. S. Bechthold, G. Gantefor, W. Eberhardt, D. S. Yang, P. A. Hackett, R. Fournier, T. Pang, and C. F. Chen, "Photoelectron spectra and geometric structures of small niobium cluster anions", Physical Review Letters 77, 4528-4531 (1996).

[61] D. S. Yang, M. Z. Zgierski, A. Berces, P. A. Hackett, P. N. Roy, A. Martinez, T. Carrington, Jr., D. R. Salahub, R. Fournier, T. Pang, and C. F. Chen, "Vibrational and geometric structures of Nb_3C_2 and Nb_3C_2^+ from pulsed field ionization-zero electron kinetic energy photoelectron spectra and density functional calculations", Journal of Chemical Physics 105, 10663-10671 (1996).

[60] X. W. Wang and C. F. Chen, "Insulating behavior of alkali-metal-covered GaAs(110)", Physical Review B 54, 13436-13439 (1996).

[59] Y. M. Gu, T. Pang, C. F. Chen, E. G. Wang, C. S. Ting, D. M. Bylander, and Leonard Kleinman, "First principles study of the quaternary semiconductor superlattices (GaX)_1/(YAs)_1", Physical Review B 54, 13784-13790 (1996).

[58] E. G. Wang, Y. Zhou, C. S. Ting, J. Zhang, T. Pang, and C. F. Chen, "Excitons in spatially separated electron-hole systems: A quantum Monte Carlo study", Journal of Applied Physics 78, 7099-7102 (1995).

[57] J. Zhang, T. Pang, and C. F. Chen, "Biexctions in Qunatum Wells: A Quantum Monte Carlo Study," Physics Letters A 206, 101-106 (1995).

[56] C. F. Chen, "Correlation induced electron-lattice interaction and its effects on the spectral distribution", Journal of Physics and Chemistry of Solids 56, 1703-1704 (1995).

[55] J. Zheng and C. F. Chen, "Coverage dependent spectral evolution in correlated systems: An exact diagonolization study of a generic overlayer model", Physical Review B 52, 8051-8059 (1995).

[54] E. G. Wang, C. F. Chen, and C. S. Ting, "Tight-binding calculation of ZnSe/Ge superlattices: Electronic structure and optical property", Journal of Applied Physics 78, 1832-1837 (1995).

[53] C. F. Chen and J. Zheng, "Single-particle excitation spectra of an extended Hubbard model with intersite interactions", Physics Letters A 201, 344-348 (1995).

[52] J. Zheng anf C. F. Chen, "Photoelectron spectroscopy of strongly correlated systems: Effects of nonlocal interactions", Physical Review B 51, 14092-15002 (1995).

[51] C. F. Chen, "Electron correlation and heavy-fermion states in the Hubbard model", Physica B 206/207, 729-731 (1995).

[50] C. F. Chen, "Open systems in contact with a ferromagnetic Fermi sea: quantum particle-number fluctuations", Physics Letters A 196, 87-96 (1994).

[49] C. F. Chen, "Interface hybridization and spectral distribution in strongly correlated itinerant magnetic systems", Physical Review B 50, 14539-14545 (1994).

[48] C. F. Chen, "Spectral function evolution in a multiband d-electron model: Combined single-particle and many-body effects", Physical Review Letters 73, 1982-1985 (1994).

[47] C. F. Chen and J. Zheng, "Electron correlation, geometrical (magnetic) frustration, and heavy-fermion behavior in a two-dimensional Hubbard model", Physics Letters A 189, 243-247 (1994).

[46] C. F. Chen, "High-spin magnetic heavy-fermion states at ferromagnetic/heavy-fermion interfaces", Physica B 194/196, 1343-1344 (1994).

[45] C. F. Chen, "Superconductivity in the fcc Hubbard model: From two to three dimensions", Physical Review B 48, 6683-6686 (1993).

[44] C. F. Chen, "Interface effects in strongly correlated metals: An exact diagonalization study of the t-t'_J model", Physics Letters A 179, 49-54 (1993).

[43] C. F. Chen, "Photoemission as a probe of electronic states in ultrathin magnetic overlayers: Correlation and hybridization effects", Physical Review B (Rapid Communications) 48, 1318-1321 (1993).

[42] C. F. Chen, "Exact diagonalization study of real materials", Materials Research Society Symposium Proceedings 291, 253-258 (1993).

[41] C. F. Chen, "Many-body theory for bcc transition-metal surfaces", Physica B 183, 271-278 (1993).

[40] C. F. Chen, "Pairing and charge density correlation in the 3D negative-U Hubbard model on the fcc lattice", Physical Review B 47, 2861-2865 (1993).

[39] C. F. Chen, "Many-body electronic structure at transition-metal surfaces: Ni(001)", Journal of Physics Condensed Matter 4, 9855-9868 (1992).

[38] C. F. Chen, "Interaction driven transfer of spectral weight in the epitaxial monolayer of Ni on Cu(001)", Physical Review B (Rapid Communications) 45, 13811-13814 (1992).

[37] C. F. Chen, "Novel many-body effects in photoemission and inverse photoemission spectra of ultrathin transition-metal films", International Journal of Modern Physics B 5, 1147-1178 (1991).

[36] V. Dobrosavljevic, T. R. Kirkpatrick, C. F. Chen, and D. Belitz, "Critical behavior of ultrasonic attenuation near interaction driven metal-insulator transitions", Physical Review B 44, 5432-5443 (1991).

[35] C. F. Chen, "A many-body theory of the electronic structures in ultrathin transition-metal films: bcc Co(001)", Physical Review B 43, 6347-6353 (1991).

[34] C. F. Chen, "Novel many-body effects in the photoemission spectrum of ultrathin bcc cobalt films", Physical Review Letters 64, 2176-2179 (1990).

[33] C. F. Chen, "Surface magnetism in an exactly soluble many-body periodic-cluster model of bcc Iron", Physical Review B 41, 1320-1326 (1990).