SciPost Phys. 5, 061 (2018) ·
published 11 December 2018
The Unruh effect is a quantum relativistic effect where the accelerated
observer perceives the vacuum as a thermal state. Here we propose the
experimental realization of the Unruh effect for interacting ultracold fermions
in optical lattices by a sudden quench resulting in vacuum acceleration with
varying interactions strengths in the real temperature background. We observe
the inversion of statistics for the low lying excitations in the Wightman
function as a result of competition between the spacetime and BCS Bogoliubov
transformations. This paper opens up new perspectives for simulators of quantum
Samuel Mugel, Alexandre Dauphin, Pietro Massignan, Leticia Tarruell, Maciej Lewenstein, Carlos Lobo, Alessio Celi
SciPost Phys. 3, 012 (2017) ·
published 15 August 2017
Topologically non-trivial Hamiltonians with periodic boundary conditions are characterized by strictly quantized invariants.
Open questions and fundamental challenges concern their existence, and the possibility of measuring them in systems with open boundary conditions and limited spatial extension.
Here, we consider transport in Hofstadter strips, that is, two-dimensional lattices pierced by a uniform magnetic flux which extend over few sites in one of the spatial dimensions.
As we show, an atomic wavepacket exhibits a transverse displacement under the action of a weak constant force.
After one Bloch oscillation, this displacement approaches the quantized Chern number of the periodic system in the limit of vanishing tunneling along the transverse direction.
We further demonstrate that this scheme is able to map out the Chern number of ground and excited bands, and we investigate the robustness of the method in presence of both disorder and harmonic trapping.
Our results prove that topological invariants can be measured in Hofstadter strips with open boundary conditions and as few as three sites along one direction.
Dr Celi: "We thank the Referee for the i..."
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