Physics & Astronomy Colloquium: Dr. Constantin Schrade, Niels Bohr Institute


Location: 127 Nieuwland Science Hall

Complex quantum matter for quantum computation and simulation

Dr. Constantin Schrade
Research Assistant Professor
Niels Bohr Institute

Quantum material science plays a pivotal role in the advancement of quantum computing and simulation platforms, particularly for solid-state hardware. For superconducting circuits, which are among the most promising platforms for solid-state quantum computing, the key open challenges are in fact closely linked to material properties and primarily concern the omnipresence of environmental errors, which are currently a severe limiting factor to the computational performance. Hence, a relevant and timely question is if novel complex quantum materials with their unique properties can provide alternative pathways to more robust, error-protected superconducting quantum computation and, more broadly, offer novel platforms for quantum simulation?

In this talk, I will address this question through the lens of two distinct quantum material platforms: hybrid quantum materials comprised of superconductors and semiconductors, as well as 2d materials. In the first part of the talk, I will describe how hybrid quantum materials when placed in contact with superconductors can give rise to an exotic 4e supercurrent and discuss preliminary experimental evidence for such a coherent transport of pairs of Cooper-pairs. I will then present resulting insights on how the 4e supercurrent can be applied to create robust superconducting qubits with potentially improved error-protection capabilities compared to present-day superconducting transmon qubits. In the second part of the talk, I will focus on 2d materials, specifically graphene-based and transition metal dichalcogenide moiré superlattices, and show that they can serve as quantum simulators for paradigmatic Hubbard models, leading to unusual spin-valley density wave states. Finally, I will present a perspective on how the ideas of the first two parts lay the foundation for the study of artificial lattices in superconducting materials for the simulation of spin systems and correlated fermion models. 

Hosted by Prof. Jin