Topological Superconductivity using Layered Materials
Abstract
Topological superconductivity (TSC) can support low energy excitations with unique properties with tremendous implications for fundamental science and applications. In their simplest form, such excitations have non-Abelian statistics that have no counterpart in particle physics. Beyond the basic interest in such excitations and the conditions under which they form, non-Abelian excitations open up exciting possibilities for quantum computation that could potentially overcome some of the limitations of conventional quantum computing approaches. Unfortunately, nature is unkind in providing materials that have TSC as an inherent property. Surprisingly, hybrid structures consisting of stacks of conventional superconductors, magnets, and semiconductors with strong spin orbit interaction have been theoretically shown to enable creation of TSC despite the fact that none of its constituents has this property. This opens up a fertile ground to search for TSC. Thus far this hybrid approach has been pursued solely using conventional bulk semiconductors and primarily nanowires which have significant limitations. Here we propose to take advantage of the tremendous breadth and flexibility of layered materials in order to create hybrid structures, demonstrate TSC in such systems, and explore the underlying non-Abelian excitations. Layered materials come in many varieties which span all known phases of matter including superconductivity, magnetism, insulators, semiconductors and more. Additionally, they often have strong spin orbit interaction needed for artificially creating a TSC. Here we propose to use such layered materials to create and explore TSC using two distinct approaches. The first consists of using WTe2 as a quantum spin Hall insulator. When coupled to conventional superconductors this phase is expected to become a TSC with localized Majorana bound states. The second approach consists of using a layered semiconductor with strong spin-orbit interaction coupled to a superconductor. When this system is subject to an in plane magnetic field it too is expected to become a TSC. Layered materials open up a vast range of possibilities in terms of the superconductors and semiconductors used and hence could be optimized to strengthen the desired physics.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 14, 2019
- Source ID
- W911NF1810316
Entities
People
- Amir Yacoby
Organizations
- Army Contracting Command
- Harvard University
- United States Army