Condensed Matter Physics Seminar
2 p.m., Thursday, September 29, 2005
Room 1201, Physics Building
Spin incoherent effects in momentum resolved tunneling and transport in
Luttinger liquids
(KITP, UC Santa Barbara)
Abstract: In an electron gas at very low density a regime can be
obtained where the magnetic exchange energy J between neighboring
electrons is exponentially suppressed relative to the Fermi energy, EF.
At finite temperature T, the energy hierarchy J << T <<
EF can be reached, and we refer to this as the spin incoherent
Luttinger liquid state. We theoretically explore the signatures of spin
incoherence in momentum resolved tunneling and in transport, and compare the
results with recent experiments. In momentum resolved tunneling the spin modes
of a Luttinger liquid are thermally washed out leaving only the charge modes in
the spectral function with a shift from +/- kF to +/- 2kF
in momentum space. These modes are also broadened in momentum space by an amount
of order kF and the energy dependence of the tunneling density
of states qualitatively changes from that of the spin coherent Luttinger liquid
regime. The effects of an external magnetic field in the spin incoherent regime
are also discussed. Transport in the infinite system can be mapped onto spinless
electrons and various crossovers in temperature and for finite systems connected
to Fermi liquid leads are also discussed.
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Host: Yakovenko
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