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Atomtronics with a spin: Statistics of spin transport and nonequilibrium orthogonality catastrophe in cold quantum gases
- Source :
- Physical Review B
- Publication Year :
- 2019
- Publisher :
- American Physical Society (APS), 2019.
-
Abstract
- We propose to investigate the full counting statistics of nonequilibrium spin transport with an ultracold atomic quantum gas. The setup makes use of the spin control available in atomic systems to generate spin transport induced by an impurity atom immersed in a spin-imbalanced two-component Fermi gas. In contrast to solid-state realizations, in ultracold atoms spin relaxation and the decoherence from external sources is largely suppressed. As a consequence, once the spin current is turned off by manipulating the internal spin degrees of freedom of the Fermi system, the nonequilibrium spin population remains constant. Thus one can directly count the number of spins in each reservoir to investigate the full counting statistics of spin flips, which is notoriously challenging in solid state devices. Moreover, using Ramsey interferometry, the dynamical impurity response can be measured. Since the impurity interacts with a many-body environment that is out of equilibrium, our setup provides a way to realize the non-equilibrium orthogonality catastrophe. Here, even for spin reservoirs initially prepared in a zero-temperature state, the Ramsey response exhibits an exponential decay, which is in contrast to the conventional power-law decay of Anderson's orthogonality catastrophe. By mapping our system to a multi-step Fermi sea, we are able to derive analytical expressions for the impurity response at late times. This allows us to reveal an intimate connection of the decay rate of the Ramsey contrast and the full counting statistics of spin flips.<br />Comment: 9+11 pages, 10 figures
- Subjects :
- Quantum decoherence
Population
FOS: Physical sciences
02 engineering and technology
01 natural sciences
Ramsey interferometry
Ultracold atom
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
0103 physical sciences
Atom
Statistics
010306 general physics
education
Condensed Matter - Statistical Mechanics
Spin-½
Physics
Quantum Physics
education.field_of_study
Condensed Matter - Mesoscale and Nanoscale Physics
Statistical Mechanics (cond-mat.stat-mech)
021001 nanoscience & nanotechnology
3. Good health
Quantum Gases (cond-mat.quant-gas)
Atomtronics
Condensed Matter::Strongly Correlated Electrons
Condensed Matter - Quantum Gases
Quantum Physics (quant-ph)
0210 nano-technology
Fermi gas
Subjects
Details
- ISSN :
- 24699969 and 24699950
- Volume :
- 99
- Database :
- OpenAIRE
- Journal :
- Physical Review B
- Accession number :
- edsair.doi.dedup.....046d45f8d6031d32272bb0d07f8a28d2