Research Interests
In our lab, we study nanoelectronic devices based on two-dimensional (2D) materials such as graphene and more complex van-der-Waals heterostructures. Our research combines advanced nanofabrication, low-temperature quantum transport measurements including spin- and valley-resolved spectroscopy techniques to probe the physics of correlated electrons and other quantum phenomena at the nanoscale.
Electrostatically defined nanostructures in bilayer graphene
We use low-temperature transport measurements to study gate-defined nanostructures such as quantum dots (QDs) [1,2] and quantum point contacts (QPCs) [3] in Bernal stacked bilayer graphene and other related 2D materials. By precisely controlling electrostatic potentials, we create confinement potentials for single electrons, which can be individually probed and manipulated.
These quantum devices serve as highly tuneable spectroscopic platforms for investigating electron-electron interactions within the quantum dots and many-body effects, exotic quantum phases as well as topological valley-dependent transport in the surrounding bilayer graphene.
Selected References:
[1] L. Banszerus et al., Nat. Commun. 12, 5250 (2021).
[2] L. Banszerus et al., Nature 618, 51–56 (2023).
[3] L. Banszerus et al., Phys. Rev. Lett. 124, 177701 (2020).
Advanced nanodevice fabrication
Our team has extensive expertise in state-of-the-art nanofabrication techniques for 2D material-based quantum devices. We utilize van-der-Waals stacking to create complex, tailor-made heterostructures with low disorder. Using high-resolution electron-beam lithography (EBL), reactive ion etching (RIE), and atomic layer deposition (ALD) we fabricate high-quality, devices with exceptional control over their electronic properties.
We have access to modern cleanroom infrastructure, allowing us to push the limits of complexity and miniaturization. These fabrication techniques enable us to realize few-electron quantum dots, ballistic nanoconstrictions, and superconductor/semiconductor hybrid devices.
Superconductor/semiconductor hybrid devices based on 2D materials
We investigate hybrid quantum devices such as Josephson junctions, superconducting quantum interference devices (SQUIDs) and superconducting tunneling junctions where either two- or three-dimensional superconductors are integrated with normal conducting 2D materials.
Such hybrid devices are of fundamental interest for studying unconventional superconducting pairing mechanisms in low-dimensional materials in the presence of a high density of states. Additionally, they can be used to probe proximity-induced superconductivity and study Andreev processes in 2D materials.
Novel superconducting circuit elements
We simulate and realize novel superconducting circuit elements based on superconductor/semiconductor hybrid materials. Such devices combine the dissipationless nature of superconducting elements with in-situ tuneability of semiconductors.
Hybrid Josephson circuits containing multiple gate-controlled Josephson junctions can for example be used to deterministically control their current-phase-relation (CPR) [1] or to realize pi-periodic Josephson potentials that only allow for tunnelling of pairs of Cooper pairs across the circuit [2]. These advanced superconducting devices are the building blocks for novel superconducting elements such as protected superconducting qubits and non-linear superconducting electronics.
Selected References:
[1] L. Banszerus et al., Phys. Rev. Lett. 133, 186303 (2024).
[2] L. Banszerus et al., Phys. Rev. X 15, 011021 (2025).