Publications [#245079] of Harold U. Baranger

Papers Published

1. Liu, D; Chandrasekharan, S; Baranger, HU, Quantum Phase Transition and Dynamically Enhanced Symmetry in Quadruple Quantum Dot System, Physical Review Letters, vol. 105 no. 25 (2010), pp. 256801 [21231607], [doi]
   (last updated on 2026/01/15)

   Abstract:
   We propose a system of four quantum dots designed to study the competition between three types of interactions: Heisenberg, Kondo, and Ising. We find a rich phase diagram containing two sharp features: a quantum phase transition (QPT) between charge-ordered and charge-liquid phases and a dramatic resonance in the charge liquid visible in the conductance. The QPT is of the Kosterlitz-Thouless type with a discontinuous jump in the conductance at the transition. We connect the resonance phenomenon with the degeneracy of three levels in the isolated quadruple dot and argue that this leads to a Kondo-like emergent symmetry from left-right Z2 to U(1).