Quantum Noise and Backaction in Semi- and Superconducting Nanostructures

*****非技术摘要*****量子力学要求测量粒子（例如电子）位置的行为将通过改变粒子的速度来影响粒子。 这种测量反作用于被测量物体的著名说法被称为海森堡不确定原理。 人们经常将测量称为对被测量对象具有某种“反作用”。 这个单一研究者奖支持直接调查这些基本问题的研究。 PI 实验室的最新技术进步催生了超灵敏电荷探测器，可以直接观察到导致反作用的噪声力。 这些探测器将用于观察被限制在半导体中称为量子点的纳米尺寸区域内的单个电子的位置。 影响电子位置的反作用力将被独立监测。 此类测量将允许直接研究不确定性原理背后的物理过程。 这项研究的结果还将对量子计算机中的比特测量产生影响，预计量子计算机能够解决经典计算机无法解决的问题。 参与该项目的学生将接受一系列先进制造和测量技术的培训，为他们在学术界、工业界或政府部门的职业生涯做好充分准备。*****技术摘要*****海森堡不确定性原理与量子系统中的噪声之间存在着深刻的关系。 由于探测器必然会影响它正在测量的系统，因此系统产生的量子力学噪声应该直接受到探测器施加在其上的噪声力（反作用）的影响。 这个单一研究者奖支持直接调查这些基本问题的研究。 PI 实验室的最新技术进步催生了超灵敏电荷探测器，可以观察到导致反作用的固有噪声。 通过使用这些探测器来监测半导体器件中单个电子的位置，这项研究将直接研究不确定性原理背后的物理过程。这项工作的结果也将对量子计算领域产生影响，其中的一个中心问题是量子比特状态的测量。参与该项目的学生将接受一系列先进制造和测量技术的培训，为他们在学术界、工业界或政府部门的职业生涯做好充分准备。

*****NON-TECHNICAL ABSTRACT*****Quantum mechanics demands that the act of measuring the position of a particle such as an electron will influence the particle by changing its velocity. The famous statement that such a measurement acts back on the object being measured is known as Heisenberg's Uncertainly Principle. One often speaks of a measurement as having some "backaction" on the object being measured. This single-investigator award supports research that will directly investigate these fundamental issues. Recent technological advances in the PI's laboratory have led to ultrasensitive charge detectors for which the noisy forces that cause to backaction can be directly observed. These detectors will be used to observe the position of a single electron confined to a nanometer-sized region in semiconductor known as a quantum dot. The backaction forces that influence the electron position will independently be monitored. Measurements like these will allow a direct investigation of the physical processes underlying the Uncertainty Principle. Results from this research will also have implications for measurement of bits in quantum computers, which are expected to be able to solve problems classical computers cannot. Students involved in this project will receive training in a broad array of advanced fabrication and measurement techniques, leaving them well-prepared for a career in academia, industry or government.*****TECHNICAL ABSTRACT*****There is a deep relationship between Heisenberg's Uncertainty Principle and noise in a quantum system. Since a detector necessarily influences a system it is measuring, the quantum mechanical noise produced by a system should be directly influenced by the noisy force (the backaction) exerted on it by a detector. This single-investigator award supports research that will directly investigate these fundamental issues. Recent technological advances in the PI's laboratory have led to ultrasensitive charge detectors for which the intrinsic noise that leads to backaction can be observed. By using these detectors to monitor the position of a single electron in a semiconductor device, this research will take a direct look at the physical processes underlying the Uncertainty Principle. Results from this work will also have implications for the field of quantum computation, in which a central problem is the measurement of the state of a quantum bit. Students involved in this project will receive training in a broad array of advanced fabrication and measurement techniques, leaving them well-prepared for a career in academia, industry or government.