Quantum Transport Measurements

Summary

We are developing the foundational knowledge and measurement infrastructure that will facilitate the use of solid state systems with emergent quantum properties in future electronic and quantum information science applications.

Description

Measuring interactions between chiral edge states. 2D heterostructure (left); magnetoresistance data (right).

It is necessary to isolate, control, and understand the fundamental physics of exotic states of matter to create nanoengineered systems with the requisite quantum properties for quantum information systems and advanced computing applications. We develop measurement capabilities and design test structures so that the fundamental properties of solid state quantum systems can be experimentally determined. At the core of this program are cryogenic measurements of novel devices, heterostructures, and the atomically engineered materials that comprise them. Transport measurements are the gold-standard for demonstrating and identifying emergent quantum properties such as superconductivity or metal/insulator transitions. This program includes the fabrication of such devices and heterostructures and their electrical and physical characterization. We are currently focused on research that will facilitate the use of topologically protected solid state electronic systems and quantum materials based on crystallographically rotated two-dimensional materials in high performance electronic and quantum information technologies.

Metrology for Quantum Topological Systems:

We perform basic experimental research to extract the fundamental properties of topologically protected solid state electronic systems. The results of these measurements are used to assess if the underlying physics in these systems can be harnessed for quantum applications such as computation and sensing. By exploiting topological systems, it may be possible to overcome decoherence, the largest barrier to building scalable quantum computers. Our focus is on chiral Majorana modes. It is predicted that these chiral states can be created by coupling superconducting materials to the topological 1D edge states in quantum anomalous Hall effect (QAHE) materials or in graphene in the quantum Hall regime. We are advancing measurements and solid state test structures that elucidate the behavior of chiral edge states in topological systems with the target of demonstrating new states that can be used in applications requiring quantum entanglement.

Making a twisted electronic device from 2D materials on a custom stacking station.

Twisted Electronics:

Engineering quantum materials by stacking atomically thin layers is a new and challenging area of research. The stacks must be formed with non-equilibrium crystallographic angles. The placement of atomically thin layers with angular control is the only way to produce twisted-angle systems to determine their emergent properties. When successfully stacked with sub-degree accuracy, it has been shown that emergent properties such as superconductivity and metal/insulator transitions can arise. We are performing basic research to develop measurements that facilitate the development of devices that harness the emergent properties of atomically engineered two-dimensional heterostructures for quantum information science applications.