Proposal for a two-channel quantum dot setup: Prediction for the capacitance lineshape

We have made a detailed proposal for a two-channel quantum dot setup. The energy scales in the problem are such that we are able to make connection with the two-channel Anderson model, which, in spite of being well-known in the context of heavy-Fermion systems remained theoretically elusive until recently and lacked a mesoscopic realization. Verification of our precise and robust predictions for the differential capacitance lineshape of the dot will provide an experimental signature of the two-channel behavior.Comment: Proceedings for SCES conference (2005

Observing Majorana Bound States in p-wave Superconductors Using Noise Measurements in Tunneling Experiments

The zero-energy bound states at the edges or vortex cores of chiral p-wave superconductors should behave like majorana fermions. We introduce a model Hamiltonian that describes the tunnelling process when electrons are injected into such states. Using a non-equilibrium green function formalism, we find exact analytic expressions for the tunnelling current and noise and identify experimental signatures of the majorana nature of the bound states to be found in the shot noise. We discuss the results in the context of different candidate materials that support triplet superconductivity. Experimental verification of the majorana character of midgap states would have important implications for the prospects of topological quantum computation.Comment: 4 pages, 1 figur

Time-Loop Formalism for Irreversible Quantum Problems: Steady State Transport in Junctions with Asymmetric Dynamics

Non-unitary quantum mechanics has been used in the past to study irreversibility, dissipation and decay in a variety of physical systems. In this letter, we propose a general scheme to deal with systems governed by non-Hermitian Hamiltonians. We argue that the Schwinger-Keldysh formalism gives a natural description for those problems. To elucidate the method, we study a simple model inspired by mesoscopic physics --an asymmetric junction. The system is governed by a non-Hermitian Hamiltonian which captures essential aspects of irreversibility.Comment: 4 pages, 4 figure