arXiv subjects

Linda E. Reichl

Publications and source records attributed to Linda E. Reichl.

9 recordsLinked to original sources

arXiv2019

Local and Nonlocal Shot Noise in High-$T_C$ Superconducting Nanowires

We obtain exact expressions for the local current and shot noise and the nonlocal shot noise in the first propagating channel of an NSN (normal-superconducting-normal) nanowire. Using high-$T_c$ cuprate superconductors (HTS) as our model systems we utilize a scattering theory approach to derive the scattering matrix for the systems in the high transparency limit and without the Andreev approximation. The local current and shot noise spectrum is calculated and plotted. In view of recent work in the area of cooper-pair splitting (CPS) devices, we investigate the nonlocal shot noise and relate the behavior of the noise as we change parameters such as the system size, the orientation of the order parameter and the biasing of the junction in the HTS NSN system.

cond-mat.supr-con↗

arXiv2017

A kinetic model for very low temperature dilute Bose gases

We review recent work on a kinetic model for very low temperature dilute Bose gases. The brief derivation, expressions for hydrodynamics modes, and the comparison with a experiment on a BEC of $^{87}{\rm Rb}$ atoms are presented.

cond-mat.quant-gas↗

arXiv2010

Quantum Control of Interacting Bosons in Periodic Optical Lattice

We study the avoided crossings in the dynamics of quantum controlled excitations for an interacting two-boson system in an optical lattice. Specifically, we perform numerical simulations of quantum control in this system where driving pulses connect the undriven stationary states in a manner characteristic of Stimulated Raman Adiabatic Passage (STIRAP). We demonstrate that the dynamics of such a transition is affected by chaos induced avoided crossings, resulting in a loss in coherence of the final outcome in the adiabatic limit.

physics.atom-ph↗

arXiv2009

Time-of-Flight Signatures of Bosons in a Double Well

We present analytical and numerical treatments for evaluating the time-of-flight momentum distribution for the stationary states of a two-boson system trapped in a quartic double-well potential, paying particular attention to the Tonks and noninteracting regimes. We find that the time-of-flight distributions can serve as a valuable tool in profiling the states of this system, and provide the tof plots for low-energy excitations using a nonadaptive finite element method that is more efficient than traditional finite difference methods.

physics.atom-ph↗

arXiv2007

Coherent Control of Trapped Bosons

We investigate the quantum behavior of a mesoscopic two-boson system produced by number-squeezing ultracold gases of alkali metal atoms. The quantum Poincare maps of the wavefunctions are affected by chaos in those regions of the phase space where the classical dynamics produces features that are comparable to hbar. We also investigate the possibility for quantum control in the dynamics of excitations in these systems. Controlled excitations are mediated by pulsed signals that cause Stimulated Raman Adiabatic passage (STIRAP) from the ground state to a state of higher energy. The dynamics of this transition is affected by chaos caused by the pulses in certain regions of the phase space. A transition to chaos can thus provide a method of controlling STIRAP.

physics.atom-ph↗

arXiv2007

STIRAP-like transitions in a harmonically-modulated optical lattice

We introduce a method for the coherent acceleration of atoms trapped in an optical lattice, using the well-known model for stimulated Raman adiabatic passage (STIRAP). Specifically, we show that small harmonic modulations of the optical lattice amplitude, with frequencies tuned to the eigenvalue spacings of three "unperturbed" eigenstates, reveals a three-state STIRAP subsystem. We use this model to realize an experimentally achievable method for transferring trapped atoms from stationary to motional eigenstates.

quant-ph↗

arXiv2006

Shot noise in an electron waveguide square root of NOT gate

We present a calculation of the shot noise in a ballistic electron waveguide square root of NOT gate. A general expression for the shot noise in the leads connected to these types of gates is shown. We then parameterize an S-matrix which qualitatively describes the action of a square root of NOT gate previously found through numerical methods for GaAs/Al_xGa_{1-x}As based waveguides systems. Using this S-matrix, the shot noise in a single output lead and across two output leads is calculated. We find that the measurement of the shot noise across two output leads allows for the determination of the fidelity of the gate itself.

quant-ph↗

arXiv2005

Coulomb entangler and entanglement testing network for waveguide qubits

We present a small network for the testing of the entanglement of two ballistic electron waveguide qubits. The network produces different output conditional on the presence or absence of entanglement. The structure of the network allows for the determination of successful entanglement operations through the measurement of the output of a single qubit. We also present a simple model of a dynamic coulomb-like interaction and use it to describe some characteristics of a proposed scheme for the entanglement of qubits in ballistic electron waveguides.

quant-ph↗

arXiv2005

Avoided crossings in driven systems

We characterize the avoided crossings in a two-parameter, time-periodic system which has been the basis for a wide variety of experiments. By studying these avoided crossings in the near-integrable regime, we are able to determine scaling laws for the dependence of their characteristic features on the non-integrability parameter. As an application of these results, the influence of avoided crossings on dynamical tunneling is described and applied to the recent realization of multiple-state tunneling in an experimental system.

physics.atom-ph↗