Charge-4e supercurrent in a two-dimensional InAs-Al superconductor-semiconductor heterostructure
Year: 2024
Type: article
Abstract: Superconducting qubits with intrinsic noise protection offer a promising approach to improve the coherence of quantum information. Crucial to such protected qubits is the encoding of the logical quantum states into wavefunctions with disjoint support. Such encoding can be achieved by a Josephson element with an unusual charge-4e supercurrent emerging from the coherent transfer of pairs of Cooper-pairs. In this work, we demonstrate the controlled conversion of a conventional charge-2e dominated to a charge-4e dominated supercurrent in a superconducting quantum interference device (SQUID) consisting of gate-tunable planar Josephson junctions. We investigate the ac Josephson effect of the SQUID and measure a dominant photon emission at twice the fundamental Josephson frequency together with a doubling of the number of Shapiro steps, both consistent with the appearance of charge-4e supercurrent. Our results present a step towards protected superconducting qubits based on superconductor-semiconductor hybrid materials.
Source: Communications Physics
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,768
Awards: Engineered Topological Superconductivity in van der Waals Heterostructures, G434337789, Quantum-Transport Phenomena in Hybrid Devices based on Nanowires, Quantum Transport Phenomena in Hybrid Devices based on Nanowrire, QUSTEC: international, interdisciplinary and intersectoral doctoral programme in Quantum Science and Technologies, Andreev qubits for scalable quantum computation
OpenAlex ID: W4391100133