Universal Spin Transport in a Strongly Interacting Fermi Gas

Details Universal Spin Transport in a Strongly Interacting Fermi Gas Universal Spin Transport in a Strongly Interacting Fermi Gas

2011-01-04

arxiv.org/abs/1101.0780v1

Nature 472, 201-204 (2011)

Physics

Condensed Matter

Quantum Gases

10 pages, 6 figures

Scientific paper

10.1038/nature09989

Transport of fermions is central in many fields of physics. Electron transport runs modern technology, defining states of matter such as superconductors and insulators, and electron spin, rather than charge, is being explored as a new carrier of information [1]. Neutrino transport energizes supernova explosions following the collapse of a dying star [2], and hydrodynamic transport of the quark-gluon plasma governed the expansion of the early Universe [3]. However, our understanding of non-equilibrium dynamics in such strongly interacting fermionic matter is still limited. Ultracold gases of fermionic atoms realize a pristine model for such systems and can be studied in real time with the precision of atomic physics [4, 5]. It has been established that even above the superfluid transition such gases flow as an almost perfect fluid with very low viscosity [3, 6] when interactions are tuned to a scattering resonance. However, here we show that spin currents, as opposed to mass currents, are maximally damped, and that interactions can be strong enough to reverse spin currents, with opposite spin components reflecting off each other. We determine the spin drag coeffcient, the spin diffusivity, and the spin susceptibility, as a function of temperature on resonance and show that they obey universal laws at high temperatures. At low temperatures, the spin diffusivity approaches a minimum value set by the ratio of the reduced Planck's constant to the atomic mass. For repulsive interactions, our measurements appear to exclude a metastable ferromagnetic state [7-9].

Affiliated with

Also associated with

No associations

Rating

Universal Spin Transport in a Strongly Interacting Fermi Gas does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Universal Spin Transport in a Strongly Interacting Fermi Gas, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Universal Spin Transport in a Strongly Interacting Fermi Gas will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-75362