Quantum Matter 'On-a-Chip' II

量子物质“片上”II

• 批准号: RGPIN-2014-06424
• 负责人: Gervais, Guillaume
• 金额: $ 5.1万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2014
• 资助国家: 加拿大
• 起止时间: 2014-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=567793
• 关键词: Quantum; Matter; Chip; II

The mid and long-term goal of our team at McGill is to elucidate new quantum phases of matter `on-a-chip' engineered in semiconductor electronic and fluidic structures. By 'quantum matter', I mean phases of matter whose behaviour is dictated by quantum rules rather than the more conventional newtonian physics that surrounds us. By `on-a-chip', I mean on a platform similar to the processors found in modern computers. Material-wise, we use extremely low-disorder GaAs/AlGaAs grown in the highest mobility (i.e. cleanest) Molecular Beam Epitaxy (MBE) facility in the World (Princeton), as well as the cleanest material in Nature, 3He near absolute zero. Starting from raw semiconducting materials, we tailor-fabricate structures for electrons, or nanoholes for quantum fluids, using cutting-edge clean room fabrication processes evolved from the nanotech community. When the existing tools simply do not exist, we develop them and at times we file them for IP protection (patent) with McGill so as to promote the tech transfer. Below are the experiments we propose to pursue under the tenure of this grant: 1) Thermodynamic Signature of a Non-abelian Quantum Phase In elementary quantum physics textbooks, we learn that all (identical) quantum particles can be classified into two categories, according to their properties upon exchange. These two types of particles are fermions (such as electrons, protons, etc) and bosons (photons, 4He, etc). While correct in three dimensions, this need not to be true in two-dimensions where quantum statistics may exist that differ from the boson and fermion case. This project intends to demonstrate the existence of such non-abelian quantum phases by way of thermodynamic measurements 'on-a-chip'. 2) Coulomb drag and Tomonaga-Luttinger Liquid in Quantum Wires In quantum physics, one-dimensional correlated states can be modeled via a theory with exact solutions known as the Tomonaga-Luttinger liquid model. Despite its mathematical elegance, little is known experimentally regarding the behaviour of one-dimensional quantum systems. We have recently been able to fabricate quantum wires coupled in the vertical geometry by less than 15 nm, a World first. This projects thus intends to unravel the Luttinger physics that is predicted to occur in clean quantum wires by way of Coulomb drag measurements. 3) A Quantum Faucet: Quantized Mass Flow at the Nanoscale A clean quantum wire has its conductance quantuzed in units of 2e^/h, i.e. it depends only on the fundamental constants e and h. The question I am posing here is: could similar physics be observed in the mass flow of a real fluid system where the pressure gradient, the analogue to a voltage drop in a device, drives the flow (as in a faucet)? This project aims to experimentally demonstrate that at the nanoscale, for a quantum system, the conductance for the pipe should be quantized in unit of G_m=2m^2/h, the fundamental quantum of mass flow. 4) 'Sonic' Black Hole and the Unruh Effect Black holes are ubiquitous in the Universe, and despite their great interest, the celebrated 'black hole evaporation' predicted by Hawking in 1974 was never confirmed by observation. In 1981, Canadian physicist Unruh showed that the Euler equation describing the flow of an inviscid fluid supports a metric that has the same mathematical structure as the Schwarzschild metric for the black hole horizon. Using similar arguments used by Hawking, Unruh predicted 'Hawking radiation' of a sonic black hole for high-speed fluid flow. This project intends to study the 'conjectured' acoustic horizon predicted to occur in transsonic fluid flow, and explore experimentally the analogy between black hole physics and fluid dynamics.

我们在McGill的团队的中长期目标是阐明半导体、电子和流体结构中“芯片上”物质的新量子相。我所说的‘量子物质’指的是由量子规则决定其行为的物质的相，而不是我们周围更传统的牛顿物理学。我所说的‘单芯片’是指在一个类似于现代计算机中的处理器的平台上。在材料方面，我们使用了世界上迁移率最高(即最干净)的分子束外延(MBE)设备(普林斯顿大学)以及自然界最干净的材料-3He接近绝对零度-生长的极低无序的GaAs/AlGaAs。从半导体原材料开始，我们使用从纳米科技界发展而来的尖端洁净室制造工艺，量身定做电子结构或量子流体的纳米空穴。当现有的工具根本不存在时，我们开发它们，有时我们向McGill申请知识产权保护(专利)，以促进技术转让。1)非阿贝尔量子相的热力学特征在基础量子物理教科书中，我们了解到所有(相同的)量子粒子可以根据它们在交换时的性质被分为两类。这两种粒子是费米子(如电子、质子等)和玻色子(如光子、4He等)。虽然在三维情况下是正确的，但在可能存在与玻色子和费米子情况不同的量子统计的二维情况下，这不一定是正确的。这个项目打算通过“芯片上”的热力学测量来证明这种非阿贝尔量子相的存在。2)量子线中的库仑阻力和Tomonaga-Luttinger液体在量子物理中，一维关联态可以通过一种称为Tomonaga-Luttinger液体模型的具有精确解的理论来建模。尽管它在数学上是优雅的，但人们对一维量子系统的实验行为知之甚少。我们最近已经能够制造出垂直几何结构中耦合的量子线，其长度小于15 nm，这是世界上第一次。因此，这个项目打算通过库仑阻力测量来解开预计将在干净的量子线中发生的吕廷格物理。3)量子水龙头：纳米尺度下的量子质量流干净的量子线的电导以2e^/h为单位量化，即它只取决于基本常数e和h。我在这里提出的问题是：在真实流体系统的质量流动中是否可以观察到类似的物理现象，在那里，压力梯度(类似于设备中的电压降)驱动着流动(如在水龙头中)？这个项目的目的是从实验上证明，在纳米尺度上，对于一个量子系统，管道的电导应该以G_m=2m^2/h为单位来量子化，这是质量流动的基本量。4)“音速”黑洞和Unruh效应黑洞在宇宙中无处不在，尽管它们引起了人们的极大兴趣，但霍金在1974年预测的著名的“黑洞蒸发”从未被观测证实。1981年，加拿大物理学家昂鲁证明，描述无粘流体流动的欧拉方程支持一种与黑洞视界的Schwarzschild度规具有相同数学结构的度规。Unruh使用了与霍金类似的论点，预测了音速黑洞在高速流体流动时的“霍金辐射”。该项目旨在研究预计将出现在跨音速流体流动中的“推测”声学视界，并从实验上探索黑洞物理和流体动力学之间的相似之处。