Interface Exchange and Topology Driven Quantum Properties in 2D systems
Abstract
Title: Interface Exchange and Topology Driven Quantum Properties in 2D systemsOur major goal in the previous project was the unambiguous discovery of the pair of Majoranas. Under certain conditions, a fermion in a superconductor can separate in space into two parts known as Majorana zero modes. Majorana zero modes (MZMs) are Fermionic states, each of which is an antiparticle of itself. MZM is required to always appear in pair together with itspartner. The nonlocality implies that MZMs are immune to local perturbations, and hence been proposed as the key ingredients of topological qubits that are protected from decoherence and are attractive building blocks for quantum computers. We have succeeded in unambiguously showingthe Majorana pair, the first clear demonstration, in the previous project period. Our research showed direct evidence of the split Majorana pair in the two-dimensional surface states of gold, a new material platform. Using an STM to probe EuS islands grown on top of gold thin film nanowires, we confirmed the Majorana pair signature, demonstrating the expected two spatiallywell separated zero bias tunneling conductance peaks aligned along the direction of the applied magnetic field.The discovery of MZMs has set the foundation for tackling the important question of the Fermion parity of different pairs of MZMs for the big challenge how to measure Fermion parity.We propose to perform by a series of measurements by coupling with another quantum system, superconductivity, for understanding the exotic Majorana interaction and which can lead to a new platform called Majorana superconducting qubits that could lead to a quantum leap in informationprocessing. Due to large spin-orbit interaction with Au the complex spin texture at the EuS/Au interface would have to be investigated as this is one of the key ingredients to observe MZM.Tuning the EuS nanostrips and electric gate control for localizing Majoranas, their decay length dependence and interaction will be studied. We seek to identify the sources of minigap states and quasi particle poisoning of the MZM in order to minimize their influence utilizing different superconductors such as Nb, NbN. We will aim for excellent resolution of MZM spectra with planar nanojunctions and superconducting counter electrode detectors. Similar to Au (111) another equally or even more viable system we will investigate is Ag (111) surface states, with its film thickness tunable lowered Fermi level is highly promising as a new platform. This makes it easier to achieve robust, well localized Majoranas.In PIs research extensive outreach program has been carried out for three decades including close participation in the nationwide STEM summer program for high school students, and undergraduate internship programs throughout the year, exposing these young students to leading edge research and the latest scientific techniques during their internship. Our research findings, including experimental data, manuscripts and conceptual comprehensions, will bedemonstrated and broadcast through journal publications, conference talks, internet or open house activities, and development of intellectual property in the fields of quantum and nanoscience, all of which will advance education of and benefit the society widely. We intend to closely collaborate with national labs for developing Majorana based information processing.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Apr 29, 2020
- Source ID
- N000142012306
Entities
People
- Jagadeesh Moodera
Organizations
- Massachusetts Institute of Technology
- Office of Naval Research
- United States Navy