39 citations · 103 across the 6 of their papers we have counts for
6 papers
One-dimensional phase transitions in a two-dimensional optical lattice
Magnus Rehn, Sara Bergkvist, Anders Rosengren +4
A phase transition for bosonic atoms in a two-dimensional anisotropic optical lattice is considered. If the tunnelling rates in two directions are different, the system can undergo…
Transition from a two-dimensional superfluid to a one-dimensional Mott insulator
Sara Bergkvist, Robert Saers, Emil Lundh +3
A two-dimensional system of atoms in an anisotropic optical lattice is studied theoretically. If the system is finite in one direction, it is shown to exhibit a transition between…
Spinful bosons in an optical lattice
Sara Bergkvist, Ian McCulloch, Anders Rosengren
We analyze the behavior of cold spin-1 particles with antiferromagnetic interactions in a one-dimensional optical lattice using density matrix renormalization group calculations. C…
Local density approximation for confined bosons in an optical lattice
Sara Bergkvist, Patrik Henelius, Anders Rosengren
We investigate local and global properties of the one-dimensional Bose-Hubbard model with an external confining potential, describing an atomic condensate in an optical lattice. Us…
Reduction of the sign problem using the meron-cluster approach
Sara Bergkvist, Patrik Henelius, Anders Rosengren
The sign problem in quantum Monte Carlo calculations is analyzed using the meron-cluster solution. The concept of merons can be used to solve the sign problem for a limited class o…
Ground state of the random-bond spin-1 Heisenberg chain
Sara Bergkvist, Patrik Henelius, Anders Rosengren
Stochastic series expansion quantum Monte Carlo is used to study the ground state of the antiferromagnetic spin-1 Heisenberg chain with bond disorder. Typical spin- and string-corr…