Non-quasiparticle corrections for a sliding charge-density wave

Abstract

The state of the electrons in a charge-density wave (CDW) sliding at arbitrary velocity and with arbitrary electron-phonon coupling constant is discussed. The mean-field framework deals directly with the quantum mechanics of a system having non-energy-eigenstate solutions. The quasiparticle approximation is replaced by a more accurate electron-hole condensate. Corrections to the uniform current, which become important at moderate electron-phonon coupling or at high CDW speed, show that the Fermi sea is swept along with a velocity slightly less than the velocity of the CDW. Corrections to the effective energy gap for photon absorption are also discussed.

Charge-density waves at intermediate coupling

“…The ground-state energy for a type 1 pair of states that an energy e above and below the FS works out to be (see Buker 1999) …”

“…Over the past three decades, there has been a wealth of data on many CDW systems accumulated, with NbSe 3 probably being the most widely investigated (see Ong & Monceau 1977;Fleming et al 1978;Fleming & Grimes 1979;Grüner & Zettl 1985;Ségransan et al 1986;Grüner 1988Grüner , 1994Ross et al 1990;Monceau 2006;Lemay et al 1999;Ringland et al 2000;Danneau et al 2002;Requardt et al 2002;Schäfer et al 2003;Sinchenko & Monceau 2003;Perucchi et al 2004;Matsuura et al 2006; see Grüner for a review). There have also been theoretical works addressing various aspects of the problem (see Allender et al 1974;Lee et al 1974;Rice 1975;Rice et al 1976Rice et al , 1979Boriack & Overhauser 1977;McMillan 1977;Wilson 1979;Horovitz 1986;Bjelis 1987;Tucker et al 1988;Eremko 1992;McKenzie & Wilkins 1992;Buker 1999).…”