arXiv subjects

J. Stockburger

Publications and source records attributed to J. Stockburger.

6 recordsLinked to original sources

arXiv2002

Non-universal power laws in transport properties of one-dimensional quantum dots

We investigate discrepancies between recent experimental results on transport through one-dimensional quantum dots and universal power laws predicted by an idealized Luttinger Liquid description. The temperature dependence of Coulomb blockade peaks in one-dimensional quantum dots obeys non-universal power-laws from which different values of the interaction strength can be deduced. We find that, depending on the temperature range, measurements probe local or global properties of the interaction. In particular, we investigate the role of contacting semiconductor quantum wires and nanotubes connected to leads through tunnel junctions and compare to recent experiments. We conclude that a conventional Luttinger Liquid description of the quantum wire does explain the observed behaviour if specific properties of either experimental setup are carefully taken into account.

cond-mat.mes-hall↗

arXiv2002

Exact c-number Representation of Non-Markovian Quantum Dissipation

The reduced dynamics of a quantum system interacting with a linear heat bath finds an exact representation in terms of a stochastic Schr{ö}dinger equation. All memory effects of the reservoir are transformed into noise correlations and mean-field friction. The classical limit of the resulting stochastic dynamics is shown to be a generalized Langevin equation, and conventional quantum state diffusion is recovered in the Born--Markov approximation. The non-Markovian exact dynamics, valid at arbitrary temperature and damping strength, is exemplified by an application to the dissipative two-state system.

cond-mat.stat-mech↗

arXiv1998

A Stochastic Liouvillian Algorithm to Simulate Dissipative Quantum Dynamics With Arbitrary Precision

An exact and efficient new method to simulate dynamics in dissipative quantum systems is presented. A stochastic Liouville equation, deduced from Feynman and Vernon's path-integral expression of the reduced density matrix, is used to describe the exact dynamics at any dissipative strength and for arbitrarily low temperatures. The utility of the method is demonstrated by applications to a damped harmonic oscillator and a double-well system immersed in an Ohmic bath at low temperatures.

cond-mat.stat-mech↗

arXiv1998

Stabilizing dynamical localization in driven tunneling

Dynamical localization of a tunneling system by means of an oscillating external field is examined for an arbitrary doublet of tunneling states. We show that the condition of an exact crossing of Floquet levels, required for localization in a symmetric system, can be substantially relaxed for tunneling systems with broken symmetry. This generalization equally applies to tunneling systems coupled to a dissipative environment.

cond-mat↗

arXiv1998

Dynamical simulation of current fluctuations in a dissipative two-state system

Current fluctuations in a dissipative two-state system have been studied using a novel quantum dynamics simulation method. After a transformation of the path integrals, the tunneling dynamics is computed by deterministic integration over the real-time paths under the influence of colored noise. The nature of the transition from coherent to incoherent dynamics at low temperatures is re-examined.

cond-mat.stat-mech↗

arXiv1997

Is the direct observation of electronic coherence in electron transfer reactions possible?

The observability of electronic coherence in electron transfer reactions is discussed. We show that under appropriate circumstances large-amplitude oscillations can be found in the electronic occupation probabilities. The initial preparation of the system is of crucial importance for this effect, and we discuss conditions under which experiments detecting electronic coherence should be feasible. The Feynman-Vernon influence functional formalism is extended to examine more general and experimentally relevant initial preparations. Analytical expressions and path integral quantum dynamics simulations were developed to study the effects of various initial preparations on the observability of electronic coherence.

cond-mat↗