QUANTUM SIMULATIONS

Our group has strong efforts in developing novel and efficient algorithms for Quantum Monte Carlo (QMC) Simulations. Work has included new Hubbard-Stratonovich decoupling schemes in "determinant" QMC, techniques to address ergodicity problems in determinant QMC, novel methods to measure superfluid densities in "world-line" QMC for interacting boson systems, new methods to measure transport quantities like the conductivity, and the merger of density functional theory and QMC.

[24.] G.G. Batrouni and R.T. Scalettar, "Anomalous Decouplings and the Fermion Sign Problem," Phys. Rev B42, 2282 (1990).
[37.] R.T. Scalettar, R.M. Noack, and R.R.P. Singh, "Ensuring Ergodicity at Large Couplings in Determinantal Monte Carlo," Phys. Rev. B44, 10502 (1991).
[43.] G.G. Batrouni and R.T. Scalettar, "World Line Quantum Monte Carlo for a One Dimensional Bose Model," Phys. Rev. B46, 9051 (1992).
[63.] N. Trivedi, R. T. Scalettar, and M. Randeria, "Superconductor-Insulator Transition in a Disordered Electronic System", Phys. Rev. B54, 3756 (1996).
[80.] C. Huscroft and R.T. Scalettar, "Evolution of the Density of States Gap in a Disordered Superconductor", Phys. Rev. Lett. 81, 2775 (1998).
[87.] Carey Huscroft, A.K. McMahan, and R.T. Scalettar, "Magnetic and Thermodynamic Properties of the Three-Dimensional Periodic Anderson Hamiltonian", Phys. Rev. Lett. 82, 2342 (1999).
[88.] R.T. Scalettar, "World--Line Quantum Monte Carlo", in ``Quantum Monte Carlo Methods in Physics and Chemistry'' edited by M. P. Nightingale and Cyrus J. Umrigar, NATO Science Series, Series C: Mathematical and Physical Sciences--Vol 525, Kluwer Academic Publishers (1999).
[93.] M. Ulmke and R. T. Scalettar, "Auxiliary-field Monte Carlo for Quantum Spin and Boson Systems", Phys. Rev. B61, 9607 (2000).
[112.] K. Held, A.K. McMahan, and R.T. Scalettar, "The Cerium Volume Collapse: Results from the merger of dynamical mean-field theory and local density approximation,'' Phys. Rev. Lett. 87, 276404 (2001).
[114.] K. Held, I.A. Nekrasov, G. Keller, V. Eyert, N. Bl\"umer, A.K. McMahan, R.T. Scalettar, T. Pruschke, V.I. Anisimov, and D. Vollhardt, "The LDA+DMFT Approach to Materials with Strong Electronic Correlations,'' in Quantum Simulations of Complex Many-Body Systems: From Theory to Algorithms, eds. J. Grotendorst, D. Marx and A. Muramatsu, NIC Series Volume 10 (NIC Directors, Forschungszentrum J{ulich), 175-209 (2002).
[120.] A. K. McMahan, K. Held, and R. T. Scalettar, "Thermodynamic and spectral properties of compressed Ce calculated by the merger of the local density approximation and dynamical mean field theory," Phys. Rev. B67, 075108 (2003).
[128.] K. Held, I.A. Nekrasov, G. Keller, V. Eyert, N. Blumer, A.K. McMahan, R.T. Scalettar, Th. Pruschke, V.I. Anisimov, and D. Vollhardt, ``Realistic investigations of correlated electron systems with LDA+DMFT'', Psi-k Newsletter 56, April, 65-103.
[142.] E.Y. Loh, J.E. Gubernatis, R.T. Scalettar, S.R. White, D.J. Scalapino, and R.L. Sugar, "Numerical Stability and the Sign Problem in the Determinant Quantum Monte Carlo Method", Intl. J. Mod. Phys. 16, 1319 (2005).
[183.] S.M. Pittman, G.G. Batrouni, and R.T. Scalettar, "Monte Carlo Study of an Inhomogeneous Blume-Capel Model," Phys. Rev. B78, 214208 (2008).
[188.] E. Khatami, C.R. Lee, Z.J. Bai, R.T. Scalettar, and M. Jarrell, "Dynamical Mean Field Theory Cluster Solver with Linear Scaling in Inverse Temperature," submitted to Phys. Rev. B.
[189.] T. Paiva, R.T. Scalettar, M. Randeria, and N. Trivedi, "Fermions in 2D Optical Lattices: Constraints on entropy for observing antiferromagnetism and superfluidity," submitted to Phys. Rev. Lett.
[190.] S. X. Yang, H. Fotso, J. Liu, T. A. Maier, K. Tomko, E. F. D'Azevedo, R. T. Scalettar, T. Pruschke, and M. Jarrell, "Parquet approximation for the 4x4 Hubbard cluster," submitted to Phys. Rev. E.