Heat transport in topological matter

NONTECHNICAL SUMMARY

This award supports research, education, and outreach activities with a goal to achieve a fundamental understanding of topological matter by investigating how heat is transported within such matter. Topological matter is a new class of materials, which exhibit uniquely robust physical properties that are exceptionally stable to environmental effects.

This property opens the door for many potential applications in measurement science, and more importantly, quantum information. These applications are related to the existence of elusive particles called anyons.

We normally think of electrons as having no parts. Yet, in topological matter they often behave as if they were made of composite particles called anyons. These anyons are promising for building the fundamental components of a quantum computer, in which topological protection would help reduce otherwise unavoidable computational errors introduced by the material's interaction with its environment.

The nature and even the existence of anyons in many systems remain hotly debated. The primary focus of this award is to develop ways to probe the existence and nature of anyons. So far, various electronic experiments have been proposed and implemented for this purpose.

Yet, electronic tools have significant limitations and do not work in systems that do not conduct electricity. However, this is not a limitation for heat transport. The key idea of this project consists of focusing on heat transport (rather than electronic transport) to understand anyons, and hence, topological matter.

This award also supports the PI's educational and outreach activities which contribute to the development of the US workforce in science, technology, engineering, and mathematics through research training of undergraduate and graduate students, writing pedagogical review articles, organization of conferences and workshops, and outreach to K-12 students and the general public.

TECHNICAL SUMMARY

This award supports research, education, and outreach activities aimed at achieving a fundamental understanding of heat transport in topological matter. The last several years have witnessed several breakthroughs in the experimental detection of quantized thermal conductance, including the observation of its fractional quantization, which gives evidence of non-Abelian anyons. Yet, many aspects of topological heat transport remain poorly understood.

The project has two research thrusts. The first one focuses on the problems of heat dissipation and the interplay of the charge and heat transport, which are crucial for the interpretation of the experimental data. The second thrust builds on the idea of thermal interferometry of anyons.

Interferometry is the most direct way to probe fractional statistics. During the last two years, there has been dramatic progress in the experimental implementation of interferometry of charged anyons. Building on these recent developments, this project will extend the idea of anyonic interferometry to neutral anyons and to systems that do not support electric currents.

The project will address several related problems in interferometry of charged and neutral anyons and in topological heat transport at ultra-low temperatures. The technical approaches will combine conformal field theory, Keldysh technique, algebraic theory of anyons, refermionization, Bethe ansatz, and other tools. The research will benefit from interaction with experimentalists from the Weizmann Institute of Science.

This award also supports the PI's educational and outreach activities which contribute to the development of the STEM workforce in the US through research training of undergraduate and graduate students, writing pedagogical review articles, organization of conferences and workshops, and outreach to K-12 students and the general public.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.