Spin transport between polarized Fermi gases near the ferromagnetic phase transition
arXiv:2306.13536 · doi:10.1103/PhysRevB.108.155303
Abstract
We theoretically study the spin current between two polarized Fermi gases with repulsive interactions near the itinerant ferromagnetic phase transition. We consider a two-terminal model where the left reservoir is fixed to be fully polarized while the polarization of the right reservoir is tuned through a fictitious magnetic field defined by the chemical-potential difference between different atomic hyperfine states. We calculate the spectra of the spin-flip susceptibility function, which displays a magnon dispersion emerging from the Stoner continuum at low momentum in the ferromagnetic phase. Based on the spin-flip susceptibility and using Keldysh Green's function formalism, we investigate the spin current induced by quasiparticle and spin-flip tunneling processes, respectively, and show their dependence on the polarization bias between two reservoirs. The one-body (quasiparticle) tunneling demonstrates a linear dependence with respect to the polarization bias. In contrast, the spin-flip process manifests a predominantly cubic dependence on the bias. While indicating an enhanced magnon tunneling in the strong-coupling regime, our results also demonstrate a characteristic behavior around the critical repulsive strength for ferromagnetic phase transition at low temperatures.
arXiv comment9 pages, 6 figures
References in corpus (46)
- Feshbach Resonances in Ultracold Gases
- Enhanced Gilbert Damping in Thin Ferromagnetic Films
- Observation of resonance condensation of fermionic atom pairs
- Spin Seebeck insulator
- Superconducting Spintronics
- Observation of the Spin-Seebeck Effect in a Ferromagnetic Semiconductor
- Crossover from a molecular Bose-Einstein condensate to a degenerate Fermi gas
- Theory of magnon-driven spin Seebeck effect
- Theory of the Spin Seebeck Effect
- The Unitary Fermi Gas: From Monte Carlo to Density Functionals
- Itinerant Ferromagnetism in a Fermi Gas of Ultracold Atoms
- Linear-response theory of spin Seebeck effect in ferromagnetic insulators
- Inhomogeneous phase formation on the border of itinerant ferromagnetism
- Interaction-driven spin precession in quantum-dot spin valves
- Quantum transport in ultracold atoms
- Josephson effect in fermionic superfluids across the BEC-BCS crossover
- Itinerant ferromagnetism of a repulsive atomic Fermi gas: a quantum Monte Carlo study
- Two-terminal transport measurements with cold atoms
- Itinerant Ferromagnetism in an Ultracold Atom Fermi Gas
- Connecting strongly correlated superfluids by a quantum point contact
- Enhanced DC Spin Pumping into a Fluctuating Ferromagnet near Tc
- Transverse Demagnetization Dynamics of a Unitary Fermi Gas
- Exploring the ferromagnetic behaviour of a repulsive Fermi gas via spin dynamics
- Strongly correlated superfluid order parameters from dc Josephson supercurrents
- Spin current noise of the spin Seebeck effect and spin pumping
- Mapping out spin and particle conductances in a quantum point contact
- Microscopic theory of spin transport at the interface between the superconductor and a ferromagnetic insulator
- Theory of spin Peltier effect
- Itinerant ferromagnetism in an atomic Fermi gas: Influence of population imbalance
- Itinerant Ferromagnetism in a polarized two-component Fermi gas
- Spin drag in an ultracold Fermi gas on the verge of a ferromagnetic instability
- Universal Spin Transport and Quantum Bounds for Unitary Fermions
- Finite-frequency spin susceptibility and spin pumping in superconductors with spin-orbit relaxation
- Spin transport in half-metallic ferromagnets
- Anomalous Transport in the Superfluid Fluctuation Regime
- On the Stability of the Repulsive Fermi Gas with Contact Interactions
- Ferromagnetic transition of a two-component Fermi gas of Hard Spheres
- Mesoscopic spin transport between strongly interacting Fermi gases
- Transverse spin diffusion in strongly interacting Fermi gases
- Dynamical spin-flip susceptibility for a strongly interacting ultracold Fermi gas
- Multi-Particle Tunneling Transport at Strongly-Correlated Interfaces
- Nonequilibrium noise as a probe of pair-tunneling transport in the BCS--BEC Crossover
- Optical spin conductivity in ultracold quantum gases
- Non-Hermitian Ferromagnetism in an Ultracold Fermi Gas
- Particle and spin transports of spin-orbit coupled Fermi gas through a Quantum Point Contact
- Dominant Andreev Reflection through Nonlinear Radio-Frequency Transport