Decoherence & Correlations in Condensed Matter Systems

退相干

• 批准号: 156202-2012
• 负责人: Stamp, Philip
• 金额: $ 6.05万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=633497
• 关键词: Decoherence; Correlations; Condensed; Matter; Systems

Quantum systems show 'entanglement' (a process whereby two distinct physical systems, even when widely separated, appear to act in concert - what Einstein called 'spooky action at a distance') andalso phase coherence. 'Decoherence' describes the mechanisms by which entanglement and phase coherence are destroyed. An understanding of decoherence is required if we are to ever make quantum computers (where it needs to be suppressed). Decoherence mechanisms play a crucial role in both the artificial systems constructed by physicists, and in the Natural world (notably in photosynthesis and in animal and bird navigation). This project will focus on: (1) Applied work on decoherence: mechanisms of decoherence in superconductors and semiconductors, in disordered solids, and in spin systems, with emphasis on (a) potentialcandidates for qubit systems (magnetic molecules, quantum dots, superconductors) and (b) candidates for fundamental tests of quantum mechanics (optomechanical systems, quantum solitons), and (c)decoherence in biological systems(photosynthetic light-harvesting molecules, 'chemical compass' molecules). This will also involve microscopic theory for polarons and excitons in biological systems,and the dynamics of dipolar spin systems and disordered dielectrics. (2) General Models of Decoherence: the 'spin bath' and oscillator bath' models, '3rd-party decoherence', decoherence in quantum critical systems, and for magnetic and superconducting quantumsolitons; and theory enabling the separation of environmental decoherence from 'intrinsic decoherence' processes such as gravitational decoherence. The goal of this project is a fully predictive theory of decoherence in solid-state & biological systems, to be applied to key problems in these fields (decoherence in qubit systems, macroscopic quantum coherence; decoherence in magnetic, superconducting, semiconducting systems, & in photosynthesis and navigation).

量子系统表现出“纠缠”（两个不同的物理系统，即使相隔很远，也会表现出一致的行为-爱因斯坦称之为“幽灵般的远距离行为”）和相位相干性。“退相干”描述了纠缠和相位相干被破坏的机制。如果我们要制造量子计算机（需要抑制它），就需要理解退相干。退相干机制在物理学家构建的人工系统和自然世界（特别是在光合作用和动物和鸟类导航中）都起着至关重要的作用。该项目将侧重于：（1）关于退相干的应用工作：超导体和半导体、无序固体和自旋系统中的退相干机制，重点是（a）量子比特系统的潜在候选者（磁性分子、量子点、超导体）和（B）量子力学基本测试的候选者（光学机械系统，量子孤子），和（c）生物系统中的退相干（光合捕光分子，“化学罗盘”分子）。这也将涉及生物系统中极化子和激子的微观理论，以及偶极自旋系统和无序自旋的动力学。(2)退相干的一般模型：“自旋浴”和振荡器浴“模型，”第三方退相干“，量子临界系统中的退相干，以及磁性和超导量子孤子;和理论，使环境退相干从”内在退相干“过程，如引力退相干分离。该项目的目标是在固态和生物系统中的退相干的完全预测理论，应用于这些领域的关键问题（量子比特系统中的退相干，宏观量子相干;磁，超导，半导体系统中的退相干，以及光合作用和导航）。