Non-Ergodic Quantum Manipulation

非遍历量子操纵

• 批准号: EP/R029075/1
• 负责人: Michael Pepper
• 金额: $ 896.09万
• 依托单位: University College London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FR029075%2F1
• 关键词: Non; Ergodic; Quantum; Manipulation

The subject of electron transport when states are localized by disorder has been an important topic in physics for a considerable time. It was first realized in 2006 that a closed quantum system in which there is both disorder and many body interactions shows a completely new regime of behaviour termed Many Body Localization, MBL. This regime is characterised by a breakdown of equilibrium statistical mechanics, it predicts a zero conductance state at a finite temperature, entanglement can spread although there is a lack of thermalisation due to the breakdown of ergodicity expressed as a violation of the Eigenstate Thermalisation Hypothesis, ETH. Ergodicity is assumed in many areas of condensed matter science, namely that a sub-system of the whole is typical of the whole and that the behaviour averaged over time is identical to that averaged over space. Consequently the fact that it does not hold in this situation allows new phenomena as does the lack of equilibration due to the ETH no longer holding. Possible new states can be formed by the application of high frequencies to MBL and these will be investigated in the project.To date there has been no sustained experimental investigation of these predictions in condensed matter systems although there is considerable activity using cold atoms which naturally form a closed quantum system. Enormous theoretical interest has been expressed in the hundreds of papers published on the topic. It is in the area of condensed matter that this new state of matter would have a major impact if realised - which is the purpose of the project. We will comprehensively investigate this regime of behaviour using semiconductor technology and the fabrication techniques used in investigating mesoscopic devices and semiconductor nanostructures. By fabricating free standing nanostructures we will ensure a closed system by drastically reducing the coupling to the phonons which act as a heat bath. The temperature of measurements will be down the milliKelvin region and the length scale of the disorder will be varied as will other parameters such as dimensionality. Electrical and thermal techniques will be utilised as probes of the MBL state. In addition to the importance for basic physics this work will be extremely significant in quantum information and topological physics as this new state provides a means of quantum protection not presently available.

当状态被疾病定位时，电子传输的主题在相当长的时间内一直是物理学的重要主题。最初在2006年意识到，既有疾病，许多身体相互作用的封闭量子系统都显示出一种全新的行为状态，称为许多人体定位MBL。该制度的特征是平衡统计力学的崩溃，它预测在有限温度下的零电导状态，尽管由于侵犯了特征征的热量假设，但纠缠不足，但由于缺乏热量而表达的牙齿分解。在许多凝结物质科学的领域中都假定了成真，即，整体的子系统是整体的典型特征，并且随着时间的推移，平均的行为与在空间上平均的行为相同。因此，在这种情况下它不存在的事实允许新现象，因为由于ETH不再持有，因此缺乏平衡。可以通过将高频应用于MBL来形成可能的新状态，并且将在项目中研究这些状态。到目前为止，尽管使用自然形成封闭量子系统的冷原子存在相当大的活​​性，但尚未对这些预测进行持续的实验研究。关于该主题的数百篇论文，已经表达了巨大的理论利益。正是在凝结的问题领域，这种新的物质状态将会产生重大影响 - 这是该项目的目的。我们将使用半导体技术以及用于研究介质设备和半导体纳米结构的制造技术的行为方式进行全面研究。通过制造自由常规的纳米结构，我们将通过大幅度降低充当热浴的声子的耦合来确保封闭的系统。测量的温度将下降到Millikelvin区域，并且该疾病的长度尺度将与其他参数（例如维度）变化。电气和热技术将被用作MBL状态的探针。除了对基本物理学的重要性外，这项工作在量子信息和拓扑物理学中将非常重要，因为这种新状态提供了目前尚不可用的量子保护手段。

项目成果

Boundary chaos: Exact entanglement dynamics

边界混沌：精确的纠缠动力学

• DOI: 10.21468/scipostphys.15.3.092
• 发表时间: 2023
• 期刊: SciPost Physics
• 影响因子: 5.5
• 作者: Fritzsch F

Quantized charge transport driven by a surface acoustic wave in induced unipolar and bipolar junctions

感应单极和双极结中表面声波驱动的量子化电荷传输

• DOI: 10.1103/physrevb.100.245401
• 发表时间: 2019
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Chung Y

Suspended two-dimensional electron gases in In0.75Ga0.25As quantum wells

In0.75Ga0.25As量子阱中悬浮的二维电子气

• DOI: 10.1063/5.0013902
• 发表时间: 2020
• 期刊: Applied Physics Letters
• 影响因子: 4
• 作者: Chen C

Certification of spin-based quantum simulators

• DOI: 10.1103/physreva.101.052344
• 发表时间: 2019-05
• 期刊: Physical Review A
• 影响因子: 2.9
• 作者: A. Bayat;B. Voisin;G. Buchs;J. Salfi;S. Rogge;S. Bose

Multiple electron pumping

• DOI: 10.1140/epjqt/s40507-023-00203-z
• 发表时间: 2023-10
• 期刊: EPJ Quantum Technology
• 影响因子: 5.3
• 作者: M. Blumenthal;Declan Mahony;Salahuddeen Ahmad;Dominique Gouveia;H. Howe;H. Beere;Thomas Mitchel