Roton-maxon excitation spectrum of Bose condensates in a shaken optical lattice

LC Ha, LW Clark, CV Parker, BM Anderson, C Chin - Physical review letters, 2015 - APS
We present experimental evidence showing that an interacting Bose condensate in a
shaken optical lattice develops a roton-maxon excitation spectrum, a feature normally …

Spectrum of density, spin, and pairing fluctuations of an attractive two-dimensional Fermi gas

C Apostoli, P Kelly, A Lopez, K Dauer, G Bertaina… - Physical Review A, 2024 - APS
We leverage random phase approximation and unbiased auxiliary-field quantum Monte
Carlo methods to compute dynamical correlations for a dilute homogeneous two …

Rotonlike instability and pattern formation in spinor Bose-Einstein condensates

M Matuszewski - Physical review letters, 2010 - APS
We show that metastable phases of an antiferromagnetic spin-1 condensate in a simple
model with pure contact interactions can exhibit a rotonlike minimum in the excitation …

Dynamical structure factor of a fermionic supersolid on an optical lattice

E Vitali, P Kelly, A Lopez, G Bertaina, DE Galli - Physical Review A, 2020 - APS
Interfacing unbiased quantum Monte Carlo simulations with state-of-the-art analytic
continuation techniques, we obtain exact numerical results for dynamical density and spin …

Detecting the superfluid critical momentum of Bose gases in optical lattices through dipole oscillations

T Saito, I Danshita, T Ozaki, T Nikuni - Physical Review A—Atomic, Molecular …, 2012 - APS
We study the stability of superflow of Bose gases in optical lattices by analyzing the Bose-
Hubbard model within the Gutzwiller mean-field approximation. We calculate the excitation …

Critical velocity of flowing supersolids of dipolar Bose gases in optical lattices

I Danshita, D Yamamoto - Physical Review A—Atomic, Molecular, and Optical …, 2010 - APS
We study superfluidity of supersolid phases of dipolar Bose gases in two-dimensional
optical lattices. We perform linear stability analyses for the corresponding dipolar Bose …

Spectrum of density and spin density fluctuations of an attractive two-dimensional Fermi gas

C Apostoli, P Kelly, A Lopez, K Dauer… - arxiv preprint arxiv …, 2024 - arxiv.org
We leverage unbiased auxiliary-field quantum Monte Carlo methods interfaced with cutting-
edge analytic continuation tools to compute from first-principles dynamical correlations for a …

On the Accuracy of Random Phase Approximation for Dynamical Structure Factors in Cold Atomic Gases

P Kelly, E Vitali - Atoms, 2021 - mdpi.com
Many-body physics poses one of the greatest challenges to science in the 21st century. Still
more daunting is the problem of accurately calculating the properties of quantum many-body …

Excitonic collective modes in Weyl semimetals

NS Srivatsa, R Ganesh - Physical Review B, 2018 - APS
Weyl semimetals are three-dimensional analogs of graphene with pointlike Fermi surfaces.
Their linear electronic dispersion leads to a window in the particle-hole excitation spectrum …

Superfluidity of Dirac fermions in a tunable honeycomb lattice: Cooper pairing, collective modes, and critical currents

S Tsuchiya, R Ganesh, A Paramekanti - Physical Review A—Atomic, Molecular …, 2012 - APS
Motivated by recent experiments on atomic Dirac fermions in a tunable honeycomb optical
lattice, we study the attractive Hubbard model of superfluidity in the anisotropic honeycomb …