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Gabriel Gonzalez

Publications and source records attributed to Gabriel Gonzalez.

24 records · Page 2Linked to original sources
arXiv2012

Relation between Poisson and Schrödinger equation in one dimension

The relation between the Poisson and Schrödinger equation in one dimension is obtained through a simple transformation. It is pointed out that this analogy between both equations can be only applied for potentials that involve a combination of attractive and repulsive delta function potentials. This relationship enables us to use elementary electrostatic results to find the exact solution of the associated quantum bound state problem in one dimension. Particularly, the result shows that it is possible to trap a single electron in a one dimensional ionic crystal.

quant-ph↗
arXiv2011

Single-electron Faraday generator

In this paper I study the posibility of inducing a single-electron current by rotating a non-magnetic conducting rod with a small tunnel junction immerse in a uniform magnetic field perpendicular to the plane of motion. I show first, by using a thermodynamic approach, the conditions needed to pump electrons around the mechanical device in the Coulomb blockade regime. I then use a density matrix approach to describe the dynamics of the single-charge transport including many-body effects. The theory shows that it is possible to have single-electron tunneling (SET) oscillations at low temperatures by satisfying conditions similar to the Coulomb blockade systems.

cond-mat.mes-hall↗
arXiv2008

Kondo effect in single-molecule magnet transistors

We present a careful and thorough microscopic derivation of the Kondo Hamiltonian for single-molecule magnets (SMMs) transistors. When the molecule is strongly coupled to metallic leads, we show that by applying a transverse magnetic field it is possible to topologically induce or quench the Kondo effect in the conductance of a SMM with either an integer or a half-integer spin S>1/2. This topological Kondo effect is due to the Berry phase interference between multiple quantum tunneling paths of the spin. We calculate the renormalized Berry phase oscillations of the two Kondo peaks as a function of the transverse magnetic field by means of the poor man's scaling. In particular, we show that the Kondo exchange interaction between itinerant electrons in the leads and the SMM pseudo spin 1/2 depends crucially on the SMM spin selection rules for the addition and subtraction of an electron and can range from antiferromagnetic to ferromagnetic. We illustrate our findings with the SMM Ni4, which we propose as a possible candidate for the experimental observation of the conductance oscillations.

cond-mat.str-el↗
arXiv2008

Quantum bouncer with quadratic dissipation

The energy loss due to a quadratic velocity dependent force on a quantum particle bouncing on a perfectly reflecting surface is obtained for a full cycle of motion. We approach this problem by means of a new effective phenomenological Hamiltonian which corresponds to the actual energy of the system and obtained the correction to the eigenvalues of the energy in first order quantum perturbation theory for the case of weak dissipation.

quant-ph↗
arXiv2006

Berry-phase blockade in single-molecule magnets

We formulate the problem of electron transport through a single-molecule magnet (SMM) in the Coulomb blockade regime taking into account topological interference effects for the tunneling of the large spin of a SMM. The interference originates from spin Berry phases associated with different tunneling paths. We show that in the case of incoherent spin states it is essential to place the SMM between oppositely spin-polarized source and drain leads in order to detect the spin tunneling in the stationary current, which exhibits topological zeros as a function of the transverse magnetic field.

cond-mat.mes-hall↗