Perfeziona i miei risultati

A Classical Picture of the Role of Vacancies andInterstitials inHelium-4

Ma, Ping ; Pollet, Lode ; Troyer, Matthias ; Zhang, Fu

In: Journal of Low Temperature Physics, 2008, vol. 152, no. 5-6, p. 156-163

Anisotropic Harper-Hofstadter-Mott model: Competition between condensation and magnetic fields

Hügel, Dario ; Strand, Hugo U. R. ; Werner, Philipp ; Pollet, Lode

In: Physical Review B, 2017, vol. 96, no. 5, p. 054431

We derive the reciprocal cluster mean-field method to study the strongly interacting bosonic Harper-Hofstadter-Mott model. The system exhibits a rich phase diagram featuring band insulating, striped superfluid, and supersolid phases. Furthermore, for finite hopping anisotropy, we observe gapless uncondensed liquid phases at integer fillings, which are analyzed by exact diagonalization. The...

Bosonic self-energy functional theory

Hügel, Dario ; Werner, Philipp ; Pollet, Lode ; Strand, Hugo U. R.

In: Physical Review B, 2016, vol. 94, no. 19, p. 195119

We derive the self-energy functional theory for bosonic lattice systems with broken U(1) symmetry by parametrizing the bosonic Baym-Kadanoff effective action in terms of one- and two-point self-energies. The formalism goes beyond other approximate methods such as the pseudoparticle variational cluster approximation, the cluster composite boson mapping, and the Bogoliubov+U theory. It...

From the Cooper Problem to Canted Supersolids in Bose-Fermi Mixtures

Anders, Peter ; Werner, Philipp ; Troyer, Matthias ; Sigrist, Manfred ; Pollet, Lode

In: Physical Review Letters, 2012, vol. 109, no. 20, p. 206401

We calculate the phase diagram of the Bose-Fermi Hubbard model on the 3d cubic lattice at fermionic half filling and bosonic unit filling by means of single-site dynamical mean-field theory. For fast bosons, this is equivalent to the Cooper problem in which the bosons can induce s-wave pairing between the fermions. We also find miscible superfluid and canted supersolid phases depending on the...