Atom diode: Variants, stability, limits, and adiabatic interpretation

An atom diode

An atom diode, i.e., a device that lets the ground state atom pass in one direction but not in the opposite direction in a velocity range is devised. It is based on the adiabatic transfer achieved with two lasers and a third laser potential that reflects the ground state.

Improvement by laser quenching of an "atom diode": a one-way barrier for ultra-cold atoms

Different laser devices working as ``atom diodes'' or ``one-way barriers'' for ultra-cold atoms have been proposed recently. They transmit ground state level atoms coming from one side, say from the left, but reflect them when they come from the other side. We combine a previous model, consisting of the stimulated Raman adiabatic passage (STIRAP) from the ground to an excited state and a state-selective mirror potential, with a localized quenching laser which produces spontaneous decay back to the ground state. This avoids backwards motion, provides more control of the decay process and theref…

可扩展的、自验证的变分量子本征求解器使用绝热预热

Scalable, self-verifying variational quantum eigensolver using adiabatic warm starts

本文提出了一种可扩展的自验证变分量子本征求解器，通过绝热预热方法避免 barren plateau 和局部极值，利用能量标准差测量认证本征态准确性。

Counteracting systems of diabaticities using DRAG controls: The status after 10 years

The task of controlling a quantum system under time and bandwidth limitations is made difficult by unwanted excitations of spectrally neighboring energy levels. In this article we review the Derivative Removal by Adiabatic Gate (DRAG) framework. DRAG is a multi-transition variant of counterdiabatic driving, where multiple low-lying gapped states in an adiabatic evolution can be avoided simultaneously, greatly reducing operation times compared to the adiabatic limit. In its essence, the method corresponds to a convergent version of the superadiabatic expansion where multiple counterdiabaticity …

Adiabatic quantum computation with Cooper pairs

We propose a new variant of the controlled-NOT quantum logic gate based on adiabatic level-crossing dynamics of the q-bits. The gate has a natural implementation in terms of the Cooper pair transport in arrays of small Josephson tunnel junctions. An important advantage of the adiabatic approach is that the gate dynamics is insensitive to the unavoidable spread of junction parameters.

Variations on the adiabatic invariance: the Lorentz pendulum

We analyze a very simple variant of the Lorentz pendulum, in which the length is varied exponentially, instead of uniformly, as it is assumed in the standard case. We establish quantitative criteria for the condition of adiabatic changes in both pendula and put in evidence their substantially different physical behavior with regard to adiabatic invariance.