Dresden 2011 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 44: Poster Session Correlated Electrons
TT 44.61: Poster
Donnerstag, 17. März 2011, 10:00–13:00, P1
Strong correlations in spinful quantum wires with multiple dynamics — •Tobias Meng1, Mehul Dixit2, Julia Meyer3, and Markus Garst1 — 1Institut für Theoretische Physik, Universität zu Köln, 50937 Köln, Germany — 2Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA — 3SPSMS, CEA-INAC/UJF-Grenoble 1, 38054 Grenoble, France
We consider a quantum wire of electrons and focus on the quantum phase transition from a strictly one-dimensional to a quasi one-dimensional electron liquid. In the low-density limit, this transition corresponds to the deformation of the 1D Wigner crystal to a zig-zag arrangement of the electrons described by an Ising order parameter. The critical properties are governed by the charge degrees of freedom, of which the spin sector remains essentially decoupled. The interaction between critical fluctuations and the gapless plasmon mode leads to an enhanced SU(2) symmetry and a suppression of the characteristic velocity. At higher densities, the electrons form one-dimensional subbands. At the transition, the second band gets filled as a function of the external gate voltage. Electrons at the bottom of the second band interact strongly due to the diverging density of states and become impenetrable. This stabilizes the electron liquid as it hinders pair-tunneling processes between the bands which generate an attractive interaction. The impenetrable electrons in the second band are further screened by plasmon excitations and the resulting polarons finally undergo a Lifshitz transition. We discuss the resulting phase diagram as a function of transverse confinement and density of the electrons.