Spin Drag and Spin-Charge Separation in Cold Fermi Gases

Journal Article · Fri Jun 29 00:00:00 EDT 2007 · Physical Review Letters

DOI:https://doi.org/10.1103/PHYSREVLETT.98.266403· OSTI ID:20953379

Polini, Marco ^[1]; Vignale, Giovanni ^[2]

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1. NEST-CNR-INFM and Scuola Normale Superiore, I-56126 Pisa (Italy)
2. Department of Physics and Astronomy, University of Missouri, Columbia, Missouri 65211 (United States)

Low-energy spin and charge excitations of one-dimensional interacting fermions are completely decoupled and propagate with different velocities. These modes, however, can decay due to several possible mechanisms. In this Letter we expose a new facet of spin-charge separation: not only the speeds but also the damping rates of spin and charge excitations are different. While the propagation of long-wavelength charge excitations is essentially ballistic, spin propagation is intrinsically damped and diffusive. We suggest that cold Fermi gases trapped inside a tight atomic waveguide offer the opportunity to measure the spin-drag relaxation rate that controls the broadening of a spin packet.

• OSTI ID: 20953379
• Journal Information: Physical Review Letters, Vol. 98, Issue 26; Other Information: DOI: 10.1103/PhysRevLett.98.266403; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
EXCITATION
FERMI GAS
FERMIONS
RELAXATION
SPIN
TRAPPING
WAVEGUIDES