Searcharxiv⌕ Search

arXiv subjects

Máté Sütő

Publications and source records attributed to Máté Sütő.

3 recordsLinked to original sources

Universal logic circuit for gate-controlled superconductor-based switches operating at liquid-helium temperatures

The observation of the gate-controlled supercurrent (GCS) effect in superconducting nanostructures initiated major research efforts toward the realisation of superconducting-based computing architectures. Here we introduce a universal logic circuit that can be a promising superconducting building block of classical hybrid supercomputers. We demonstrate a functionally complete set of logic gates by realising the AND, OR, NOT and COPY gates. The general layout and scalability of our device, combined with recent experiments demonstrating fast switching and small voltage signals, make it a functional candidate in superconducting electronics. Our device enables the realization of all classical logic gates and the half-adder combinational logic circuit using at most three nanowires, each uniquely configured with two side-gate electrodes.

cond-mat.mes-hall↗

Determination of the current-phase relation of an InAs 2DEG Josephson junction with a microwave resonator

Semiconductor-superconductor hybrid nanocircuits are of high interest due to their potential applications in quantum computing. Semiconductors with a strong spin-orbit coupling and large $g$-factor are particularly attractive since they are the basic building blocks of novel qubit architectures. However, for the engineering of these complex circuits, the building blocks must be characterized in detail. We have investigated a Josephson junction where the weak link is a two-dimensional electron gas (2DEG) hosted in an InAs/InGaAs heterostructure grown on a GaAs substrate. We employed the in-situ epitaxially grown Al layer as superconducting contacts to form an rf SQUID, and also to create a microwave resonator for sensing the Josephson inductance. We determined the gate-dependent current-phase relation, and observed supercurrent interference in out-of-plane magnetic fields. With the application of an in-plane magnetic field, we induced asymmetry in the interference pattern, which was found to be anisotropic in the device plane.

cond-mat.mes-hall↗

Near-surface InAs 2DEG on a GaAs substrate: characterization and superconducting proximity effect

We have studied a near-surface two-dimensional electron gas based on an InAs quantum well on a GaAs substrate. In devices without a dielectric layer we estimated large electron mobilities on the order of $10^5$ cm$^2$/Vs. We have observed quantized conductance in a quantum point contact, and determined the g-factor. Using samples with an epitaxial Al layer, we defined multiple Josephson junctions and found the critical current to be gate tunable. Based on multiple Andreev reflections the semiconductor-superconductor interface is transparent, with an induced gap of 125 $μ$eV. Our results demonstrate the viability of this platform for hybrid topological superconductor devices.

cond-mat.mes-hall↗