INVESTIGADORES
NAON Carlos Maria
artículos
Título:
Heat transport through quantum Hall edge states: Tunneling versus capacitive coupling to reservoirs
Autor/es:
HUGO A. AITA; LILIANA ARRACHEA; CARLOS NAÓN; EDUARDO FRADKIN
Revista:
PHYSICAL REVIEW B - CONDENSED MATTER AND MATERIALS PHYSICS
Editorial:
APS
Referencias:
Lugar: Nueva York; Año: 2013 vol. 88 p. 85122 - 85135
ISSN:
0163-1829
Resumen:
We study the heat transport along an edge state of a two-dimensional
electron gas in the quantum Hall regime, in contact to two
reservoirs at different temperatures. We consider two exactly
solvable models for the edge state coupled to the reservoirs. The
first one corresponds to filling $\nu=1$ and tunneling coupling to
the reservoirs. The second one corresponds to integer or fractional
filling of the sequence $\nu=1/m$ (with $m$ odd), and capacitive
coupling to the reservoirs. In both cases we solve the problem by
means of non-equilibrium Green function formalism. We show that heat
propagates chirally along the edge in the two setups. We identify
two temperature regimes, defined by $\Delta$, the mean level spacing
of the edge. At low temperatures, $T< \Delta$, finite size effects
play an important role in heat transport, for both types of
contacts. The nature of the contacts manifest themselves in
different power laws for the thermal conductance as a function of
the temperature. For capacitive couplings a highly non-universal
behavior takes place, through a prefactor that depends on the length
of the edge as well as on the coupling strengths and the filling
fraction. For larger temperatures, $T>\Delta$, finite-size effects
become irrelevant, but the heat transport strongly depends on the
strength of the edge-reservoir interactions, in both cases. The
thermal conductance for tunneling coupling grows linearly with $T$,
whereas for the capacitive case it saturates to a value that depends
on the coupling strengths and the filling factors of the edge and
the contacts.