High Performance Computer Cluster

Final Report Abstract

The computer cluster has been used for the simulations of strongly correlated quantum systems with various numerical methods ranging from quantum Monte Carlo (QMC) algorithms to different variants of density matrix renormalization group (DMRG) implementations, including dynamic DMRG. Typical physical systems range from correlated ultracold gases in optical lattices to condensed matter models for one dimensional quantum wires and two dimensional antiferromagnets. The results contributed to several DFG projects, 6 diploma thesis, 7 Ph.D. thesis and 12 publications so far. Some highlights are: Detailed predictions for the density distribution in trapped fermion systems, demonstrating a crossover to a spin-incoherent Wigner crystal state as a function of density and interactions. - New predictions for the supersolid phase transitions and impurity effects in frustrated hard-core boson systems. - New results on transport and tunneling in inhomogeneous quantum wires, which demonstrate unconventional renormalization effects. - Method development for efficient dynamical simulations of quantum gases.

Publications

• Local Density of States for Individual Energy Levels in finite Quantum Wires. Phys. Rev. Lett. 101, 206401 (2008)
  Imke Schneider, Alexander Struck, Michael Bortz, and Sebastian Eggert
  
• Attractively bound pairs of atoms in the Bose-Hubbard model and antiferromagnetism. Phys. Rev. A 79, 063634 (2009)
  Bernd Schmidt, Michael Bortz, Sebastian Eggert, Michael Fleischhauer, and David Petrosyan
  
• Wigner crystal vs. Friedel oscillations in the 1D Hubbard model. Phys. Rev. B 79, 195114 (2009)
  Stefan A. Söffing, Michael Bortz, Imke Schneider, Alexander Struck, Michael Fleischhauer and Sebastian Eggert
  
• Static impurities in a supersolid of interacting hard-core bosons on a triangular lattice. Phys. Rev. B 82, 220501(R) (2010)
  Xue-Feng Zhang, Yu-Chuan Wen, and Sebastian Eggert
  
• Density profile of interacting Fermions in a one-dimensional optical trap. Phys. Rev. A 84, 021602(R) (2011)
  Stefan A. Söffing, Michael Bortz, and Sebastian Eggert
  
• Dynamical simulation of integrable and non-integrable models in the Heisenberg picture. Phys. Rev. Lett. 106, 077202 (2011)
  D. Muth, R. G. Unanyan, and M. Fleischhauer
  
• Particle number conservation in quantum manybody simulations with matrix product operators. J. Stat. Mech., 2011, P11020
  D. Muth
  
• Supersolid phase transitions for hardcore bosons on a triangular lattice. Phys. Rev. B 84, 174515 (2011)
  Xue-Feng Zhang, Raoul Dillenschneider, Yue Yu, and Sebastian Eggert
  
• Three-body interactions on a triangular lattice. Phys. Rev. B. 83 184513 (2011)
  Xue-Feng Zhang, Yu-Chuan Wen, Yue Yu
  
• Low-energy local density of states of the 1D Hubbard model
  Stefan A. Soeffing, Imke Schneider, and S. Eggert
  
• Transport and scattering in inhomogeneous quantum wires
  N. Sedlmayr, J. Ohst, I. Affleck, J. Sirker, and S. Eggert
  
• Transport induced melting of Rydberg crystals in a one dimensional lattice
  A. Lauer, D. Muth, and M. Fleischhauer