arXiv:1205.2125 · Physical Review B

Junctions of multiple quantum wires with different Luttinger parameters

Chang-Yu Hou, Armin Rahmani, Adrian E. Feiguin, Claudio Chamon

Published Aug 22, 2012• 33 citations

Abstract

Within the framework of boundary conformal field theory, we evaluate the conductance of stable fixed points of junctions of two and three quantum wires with different Luttinger parameters. For two wires, the physical properties are governed by a single effective Luttinger parameter for each of the charge and spin sectors. We present numerical density-matrix-renormalization-group calculations of the conductance of a junction of two chains of interacting spinless fermions with different interaction strengths, obtained using a recently developed method [Phys. Rev. Lett. 105, 226803 (2010)]. The numerical results show very good agreement with the analytical predictions. For three spinless wires (i.e., a Y junction) we analytically determine the full phase diagram and compute all fixed-point conductances as a function of the three Luttinger parameters.

DOI: 10.1103/physrevb.86.075451

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arXiv:1205.2125 · Physical Review B

Junctions of multiple quantum wires with different Luttinger parameters

Chang-Yu Hou, Armin Rahmani, Adrian E. Feiguin, Claudio Chamon

Published Aug 22, 2012• 33 citations

arXiv HTML PDF

Abstract

DOI: 10.1103/physrevb.86.075451

Related papers

General method for calculating the universal conductance of strongly correlated junctions of multiple quantum wires

Armin Rahmani, Chang-Yu Hou, Adrian E. Feiguin +3 more

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g

and conjecture its functional dependence on

g

g,{g}_{3}>0

) there is only one stable fixed point, corresponding to the complete separation of the wires. For attractive interaction (

g<0

and/or

{g}_{3}<0

) four fixed points are found, the stability of which depends on the interaction strength. We confirm our previous weak-coupling result of lines of fixed points for special values of the interaction parameters reaching into the strong-coupling domain. We find new fixed points not discussed before, even at the symmetric line

g={g}_{3}

, at variance with the results of M. Oshikawa et al. [J. Stat. Mech. (2006) P02008]. The pair-tunneling phenomenon conjectured by the latter authors is not found by us.