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

Gregory A. Fiete

(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.
Host:  Yakovenko
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