Probing the optical conductivity of trapped charge-neutral quantum gases

Abstract

We study a harmonically confined atomic gas which is subjected to an additional external potential such as an optical lattice. Using a linear response formulation, we determine the response of the gas to a small, time-dependent displacement of the harmonic trap and derive a simple exact relation showing that the centre-of-mass position of the atomic cloud is directly related to the global optical conductivity of the system. We demonstrate the usefulness of this approach by calculating the optical conductivity of bosonic atoms in an optical lattice. In the Mott insulating phase, there is clear evidence of an optical Mott gap, providing a proof-of-principle demonstration that the global optical conductivity gives high-quality information about the exci- tations of strongly-correlated quantum gases.

arXiv comment6 pages, 2 figures. Published version

References in corpus (24)

• Quantum phase transition from a superfluid to a Mott insulator in a gas of ultracold atoms
• Cold bosonic atoms in optical lattices
• The pseudogap in high-temperature superconductors: an experimental survey
• Synthetic magnetic fields for ultracold neutral atoms
• A Mott insulator of fermionic atoms in an optical lattice
• Revealing the Superfluid Lambda Transition in the Universal Thermodynamics of a Unitary Fermi Gas
• Using photoemission spectroscopy to probe a strongly interacting Fermi gas
• Universal Quantum Viscosity in a Unitary Fermi Gas
• Conduction of Ultracold Fermions Through a Mesoscopic Channel
• Universal Spin Transport in a Strongly Interacting Fermi Gas
• Bose-Einstein Condensates with Large Number of Vortices
• Observation of Quantized Conductance in Neutral Matter
• The spin Hall effect in a quantum gas
• Phenomenology of the normal state in-plane transport properties of high-$T_c$ cuprates
• Reaching Fractional Quantum Hall States with Optical Flux Lattices
• Transverse Demagnetization Dynamics of a Unitary Fermi Gas
• Universal spin dynamics in two-dimensional Fermi gases
• Topological p_x+ip_y Superfluid Phase of Fermionic Polar Molecules
• Phase-slip induced dissipation in an atomic Bose-Hubbard system
• Excited states of a dilute Bose-Einstein condensate in a harmonic trap
• Spectroscopy for cold atom gases in periodically phase-modulated optical lattices
• Modulation Spectroscopy and Dynamics of Double Occupancies in a Fermionic Mott Insulator
• Rapidly Rotating Fermi Gases
• Dynamics of harmonically confined systems: some rigorous results

Cited by in corpus (11)

• Measuring quantized circular dichroism in ultracold topological matter
• Conductivity spectrum of ultracold atoms in an optical lattice
• Intrinsic Anomalous Hall Effect in a Bosonic Chiral Superfluid
• Lieb's Theorem and Maximum Entropy Condensates
• Optical spin transport theory of spin-1/2 topological Fermi superfluids
• Optical spin conductivity in ultracold quantum gases
• Anomalous Hall effect in single-band chiral superconductors from impurity superlattices
• Intrinsic anomalous Hall effect across the magnetic phase transition of a spin-orbit-coupled Bose-Einstein condensate
• Spin conductivity spectrum and spin superfluidity in a binary Bose mixture
• Emergence of Sound in a Tunable Fermi Fluid
• Dynamical conductivity of disordered quantum chains