****Technical Abstract**** This project will demonstrate non-abelian quantum statistics using Majorana particles in low-dimensional systems. In contrast with bosons and fermions, when two Majoranas exchange positions their final quantum state is not identical to the starting state. Experiments on nanoscale devices will combine low-temperature mesoscopic transport measurements, microwave quantum bit manipulation techniques and the development of new materials. The goal of the proposal will be reached by putting together three building blocks of a Majorana quantum bit. Specifically, the project will investigate (1) ways to suppress decoherence of Majoranas due to non-equilibrium quasiparticles in superconductors; (2) whether the quantum state of two Majoranas can be measured; (3) how to perform the exchange, or "braiding", of Majoranas in space. The success of this proposal will lay the foundation for future topological quantum computation. The demonstration of non-abelian statistics will have an impact on science education at the basic textbook level and bring deeper awareness by the society at large of the fundamental laws governing the quantum world. The project will train a graduate student, which develop fundamental and practical skills such as nanofabrication and laboratory techniques at low temperatures. A new course on Quantum Transport aimed at graduate students and senior undergraduates will be developed with a special emphasis on topological effects.
Particles that comprise our world at the microscopic scale are divided in two classes: fermions and bosons. They obey strange rules of quantum mechanics. For example, two electrons, which are fermions, cannot be at the same place at the same time, while for photons, which are bosons, this is perfectly allowed. This project will attempt to demonstrate a new, third class of particles called the non-abelian anyons. All electrons are indistinguishable, which means that our world looks exactly the same if two of them change their places. But if two non-abelian particles are interchanged the Universe transitions into a different state dictated by the laws of topology. The particular class of anyons that will be studied here are Majorana quasiparticles, which are their own antiparticles and can be created in nanoscale devices similar to transistors. The success of this proposal will lay a foundation for future topological quantum computation which relies on interchanging, or "braiding" of non-Abelian particles. The demonstration of non-Abelian particles will have an impact on science education at the basic textbook level and bring deeper awareness by the society at large of the fundamental laws governing the quantum world. The project will train a graduate student, which develop fundamental and practical skills such as nanofabrication and laboratory techniques at low temperatures. A new course on Quantum Transport aimed at graduate students and senior undergraduates will be developed with a special emphasis on topological effects. To aid in broad dissemination and sharing of scientific knowledge, websites for rapid discussions of new results, as well as for access to raw data and talks will be developed.
