Phonon-mediated drag at ν=1/2: A test of the Chern-Simons composite-fermion theory

Abstract

We report on a study of the phonon-mediated frictional drag between two-dimensional electron layers at the Landau-level filling factor ϭ1/2 predicted by Chern-Simons composite-fermion theory. Frictional drag between widely spaced layers is dominated by the phonon-mediated interaction and is altered from its zero-field form because of the large composite-fermion effective mass and, less strongly, by magnetic local-field effects. We find that the reduced drag resistance (T)/T 2 peaks at a larger temperature and has a different density dependence than at zero field. We compare these results with recent experimental findings.

Coulomb drag

“…The theory of Coulomb drag between two 2DEGs was extended to dilute 2D hole systems (Hwang et al, 2003) and to the cases where one allows for certain tunneling processes between the layers (Oreg and Halperin, 1999;Oreg and Kamenev, 1998), interlayer disorder correlations (Gornyi et al, 1999;Hu, 2000a), in-plane potential modulation (Alkauskas et al, 2002), and disorder inhomogeneities (Apalkov and Raikh, 2005;Spivak and Kivelson, 2005;Zou et al, 2009Zou et al, , 2010. Theory of Coulomb drag between composite fermions was generalized to include phonon-mediated coupling (Bønsager et al, 2000;Khveshchenko, 2000). Mutual friction was also suggested to occur between non-Fermi-Liquid phases including Luttinger liquids (Flensberg, 1998;Klesse and Stern, 2000;Nazarov and Averin, 1998), Wigner crystals (Baker and Rojo, 2001;Braude and Stern, 2001), and strongly localized electrons (Raikh and von Oppen, 2002).…”

Frictional magnetodrag between spatially separated two-dimensional electron systems: Coulomb versus phonon mediated electron–electron interaction

“…Up to now, however, it is rare to find theoretical works on the frictional drag mediated by phonon exchange in a finite magnetic field. The exceptions are recent treatments of the phonon drag at the Landau level filling factor ν = 1/2 by Chern-Simons composite fermion theory [51,52].…”