Interaction-Assisted Reversal of Thermopower with Ultracold Atoms

  title={Interaction-Assisted Reversal of Thermopower with Ultracold Atoms},
  author={Samuel H{\"a}usler and Philipp Fabritius and Jeffrey Mohan and Martin Lebrat and Laura Corman and Tilman Esslinger},
  journal={arXiv: Quantum Gases},
We study thermoelectric currents of neutral, fermionic atoms flowing through a mesoscopic channel connecting a hot and a cold reservoir across the superfluid transition. The thermoelectric response results from a competition between density-driven diffusion from the cold to the hot reservoir and the channel favoring transport of energetic particles from hot to cold. We control the relative strength of both contributions to the thermoelectric response using an external optical potential in both… 

Figures and Tables from this paper

Transport in the two-dimensional Fermi-Hubbard model: Lessons from weak coupling
We use quantum kinetic theory to calculate the thermoelectric transport properties of the 2D single band Fermi-Hubbard model in the weak coupling limit. For generic filling, we find that the
Generation of spin currents by a temperature gradient in a two-terminal device
Theoretical and experimental studies of the interaction between spins and temperature are vital for the development of spin caloritronics, as they dictate the design of future devices. In this work,
Quantum emulation of topological magneto-optical effects using ultracold atoms
Magneto-optical effect is a fundamental but broad concept in magnetic mediums. Here we propose a scheme for its quantum emulation using ultracold atoms. By representing the light-medium interaction
Detecting Preformed-Pair Current through Nonequilibrium Noise in the BCS--BEC Crossover
Hiroyuki Tajima, ∗ Daigo Oue, 3 Mamoru Matsuo, 4, 5, 6 and Takeo Kato Department of Physics, Graduate School of Science, The University of Tokyo, Tokyo, 113-0033, Japan The Blackett Laboratory,


Breakdown of the Wiedemann–Franz law in a unitary Fermi gas
This work represents a fermionic analog of the fountain effect observed with superfluid helium and poses challenges for microscopic modeling of the finite temperature dynamics of the unitary Fermi gas.
A Thermoelectric Heat Engine with Ultracold Atoms
Thermoelectricity in a fermionic cold atoms channel in the ballistic and diffusive regimes, connected to two reservoirs is demonstrated, showing that the magnitude of the effect and the efficiency of energy conversion can be optimized by controlling the geometry or disorder strength.
Conduction of Ultracold Fermions Through a Mesoscopic Channel
A cold-atom analog of a mesoscopic conductor is engineered and studied and induced a current through the channel and found ohmic conduction, even when the channel is ballistic, which opens the way toward quantum simulation of mesoscopic devices with quantum gases.
Josephson effect in fermionic superfluids across the BEC-BCS crossover
It is shown that the relative population and phase are canonically conjugate dynamical variables throughout the crossover from the molecular Bose-Einstein condensate (BEC) to the Bardeen-Cooper-Schrieffer (BCS) superfluid regime and the dynamics of the superfluids become dissipative, which is ascribed to the propagation of vortices through the superfluid bulk.
Connecting strongly correlated superfluids by a quantum point contact
This work studied resonantly interacting Fermi gases connected by a tunable, ballistic quantum point contact, finding a nonlinear current-bias relation at low temperature that agrees quantitatively with a theoretical model in which the current originates from multiple Andreev reflections.
Observing the drop of resistance in the flow of a superfluid Fermi gas
These results show that, as in solid-state systems, current and resistance measurements in quantum gases provide a sensitive probe with which to explore many-body physics and could be applied as a probe for optical lattices and disordered systems, paving the way for modelling complex superconducting devices.
Spin entropy as the likely source of enhanced thermopower in NaxCo2O4
The finding—that spin-entropy dominates the enhancement of thermopower in transition-metal oxides—for the search for better Peltier materials is discussed.
Quantum transport in ultracold atoms
Ultracold atoms confined by engineered magnetic or optical potentials are ideal to study phenomena otherwise difficult to realize or probe in the solid state, thanks to the ability to control the
Second sound and the superfluid fraction in a Fermi gas with resonant interactions
The measurements allow us to extract the temperature dependence of the superfluid fraction, a previously inaccessible quantity that will provide a benchmark for theories of strongly interacting quantum gases.