Spin Control in One-Dimensional Quantum Dots

* 技术摘要 * 该项目旨在设计和操纵由碳纳米管制成的一维量子点中的电子量子态。超短碳纳米管是一维势阱的实验表示，其中允许的能级间距强烈依赖于纳米管的长度。通过隧道结将纳米管的一小部分耦合到铁磁或超导电极，可以实现对纳米管上电子量子态的精细控制。这些量子态将通过电导和电流散粒噪声测量来研究，这将强烈依赖于电子的自旋。该项目将支持研究生和本科生的教育，他们将接受尖端纳米纤维和低温测量技术的实践培训。除了探索定制设计和控制电子量子态的基本问题外，研究结果还将作为开发新型自旋量子器件的基础。特别是，创造和观察难以捉摸的马约拉纳费米子的可能性将对物理学的基本理解和未来的拓扑量子计算技术产生巨大影响。非技术摘要 * 电子是基本粒子，具有称为自旋的内在量子特性，可以是“向上”或“向下”。在量子力学中，电子具有自旋粒子的所有性质，但它们也表现为波。由于它们的波动性质，一维导线中电子的能量只能取某些允许的值-就像吉他弦上演奏的音符取决于弦的长度一样，量子导线中电子的能量取决于导线的长度。该项目旨在设计和操纵短节碳纳米管中电子的能态和自旋。这将通过使用铁磁和超导电极的自旋敏感配置的电气测量来实现。该项目将支持研究生和本科生的教育，他们将在接近绝对零度的温度下接受尖端纳米纤维和测量技术的实践培训。 除了探索定制设计和控制电子量子态的基本物理学之外，研究结果还将作为开发新型自旋量子器件的基础。该项目提供了一个独特的机会来创造和观察一种新的物质状态，这将使从根本上容错的量子计算技术的发展成为可能。

****TECHNICAL ABSTRACT****The project aims to design and manipulate quantum states of electrons in one-dimensional quantum dots fabricated from carbon nanotubes. Ultrashort carbon nanotubes are experimental representations of a one-dimensional potential well, in which the allowed energy level spacing depends strongly on the length of the nanotube. By coupling a short section of a nanotube to ferromagnetic or superconducting electrodes via tunnel junctions, one can achieve fine control of the electronic quantum states on the nanotube. These quantum states will be studied through conductance and current shot noise measurements, which will depend strongly on the spins of the electrons. This project will support the education of graduate and undergraduate students, who will receive hands-on training in cutting-edge nanofabrication and low-temperature measurement techniques. In addition to exploring the fundamental issues of custom-designing and controlling quantum states of electrons, the results will serve as the basis for development of novel spin-based quantum devices. In particular, the possibility of creating and observing elusive Majorana fermions would have an enormous impact on both the fundamental understanding of physics and the future topological quantum computing technology.****NON-TECHNICAL ABSTRACT****Electrons are elementary particles with an intrinsic quantum property called spin, which can be either "up" or "down". In quantum mechanics, electrons have all the properties of particles with spin, but they also behave as waves. As a consequence of their wave nature, the energies of electrons in a one-dimensional wire can only take certain allowed values - just like the note played on a guitar string depends on the length of the string, the energy of an electron in a quantum wire depends on the length of the wire. This project aims to design and manipulate the energy states and the spins of electrons in short sections of carbon nanotubes. This will be achieved via electrical measurements that will use spin-sensitive configurations of ferromagnetic and superconducting electrodes. This project will support the education of graduate and undergraduate students, who will receive hands-on training in cutting-edge nanofabrication and measurement techniques at temperatures close to absolute zero. In addition to exploring the fundamental physics of custom-designing and controlling quantum states of electrons, the results will serve as the basis for development of novel spin-based quantum devices. The project offers a unique opportunity to create and observe a new state of matter, which would enable the development of fundamentally fault-tolerant quantum computing technology.