Wires with Quantum Memory

基于双区间Sturm-Liouville理论的急剧弯曲导线上的量子力学

Quantum Mechanics on Sharply Bent Wires via Two-Interval Sturm-Liouville Theory

本文提出用双区间Sturm-Liouville理论导出的三个边界条件参数近似弯曲区域物理，以处理高度弯曲导线上强且不可积几何势下的量子力学问题，该方法在未知导线精确形状时是必要方案。

Quantum Wires and Quantum Dots for Neutral Atoms

By placing changeable nanofabricated structures (wires, dots, etc.) on an atom mirror one can design guiding and trapping potentials for atoms. These potentials are similar to the electrostatic potentials which trap and guide electrons in semiconductor quantum devices like quantum wires and quantum dots. This technique will allow the fabrication of nanoscale atom optical devices.

Globally controlled quantum wires for perfect qubit transport, mirroring and computing

It is expected that quantum wires (q-wires), will be required to transport quantum information within many quantum computer implementations. Here we describe a new design for a q-wire with perfect transmission using a uniformly coupled Ising spin chain subject to global (homogeneously-applied) pulses. Besides allowing for perfect transport of single qubits, the design also yields the perfect ``mirroring'' of multiply encoded qubits within the wire. We further utilise this global-pulse generated perfect mirror operation as a ``clock cycle'' to perform universal quantum computation on these mult…

Quantum Wire as Open System

The faithful exchange of quantum information will soon become one of the challenges of the emerging quantum information technology. One of the possible solutions is to transfer a superposition through a chain of properly coupled spins. Such a system is called a quantum wire. We discuss the transfer in a quantum wire \cite{christ,niko1,niko2}, when the process of thermalization of the state takes place together with the free evolution. We investigate which encoding scheme is more faithful in certain thermal conditions.

Wire Recycling for Quantum Circuit Optimization

Quantum information processing is expressed using quantum bits (qubits) and quantum gates which are arranged in the terms of quantum circuits. Here, each qubit is associated to a quantum circuit wire which is used to conduct the desired operations. Most of the existing quantum circuits allocate a single quantum circuit wire for each qubit and, hence, introduce a significant overhead. In fact, qubits are usually not needed during the entire computation but only between their initialization and measurement. Before and after that, corresponding wires may be used by other qubits. In this work, we …

Optimal dynamics for quantum-state and entanglement transfer through homogeneous quantum wires

It is shown that effective quantum-state and entanglement transfer can be obtained by inducing a coherent dynamics in quantum wires with homogeneous intrawire interactions. This goal is accomplished by tuning the coupling between the wire endpoints and the two qubits there attached, to an optimal value. A general procedure to determine such value is devised, and scaling laws between the optimal coupling and the length of the wire are found. The procedure is implemented in the case of a wire consisting of a spin-1/2 XY chain: results for the time dependence of the quantities which characterize …