arXiv subjects

Laura Borgongino

Publications and source records attributed to Laura Borgongino.

4 recordsLinked to original sources

arXiv2025

Supercurrent Time Division Multiplexing with Solid-State Integrated Hybrid Superconducting Electronics

Time-division multiplexing of cryogenic signals is a promising approach to reduce space requirements, shorten cooldown times, and increase the number of quantum devices measured per cooldown. We demonstrate time-division multiplexing of non-dissipative supercurrents using voltage-controlled hybrid superconducting demultiplexers. These chips integrate superconducting Josephson Field Effect Transistors including Al superconducting electrodes, proximitized semiconducting InAs channels, and hafnium oxide gate insulators. Each transistor fully suppresses the switching current and increases the resistance 20 times under a gate voltage of -4.5 V. A demultiplexer with one input and eight outputs showed a non-dissipative input range of +-2 uA, operating up to 100 MHz in signal frequency and 100 kHz in switching frequency at 50 mK. It achieved near-zero insertion loss in the superconducting state and an ON/OFF ratio of 17.5 dB. By optimizing the signal layout, the operation was extended up to 4 GHz using a demultiplexer with two outputs.

cond-mat.supr-con↗

arXiv2025

The Ferroelectric Superconducting Field Effect Transistor

The ferroelectric field-effect transistor (Fe-FET) is a three-terminal semiconducting device first introduced in the 1950s. Despite its potential, a significant boost in Fe-FET research occurred about ten years ago with the discovery of ferroelectricity in hafnium oxide. This material has been incorporated into electronic processes since the mid-2000s. Here, we observed ferroelectricity in a superconducting Josephson FET (Fe-JoFET) operating at cryogenic temperatures below 1 Kelvin. The Fe-JoFET was fabricated on the InAsOI platform, which features an InAs epilayer hosted by an electrical insulating substrate, using HfO2 as the gate insulator, making it a promising candidate due to its ferroelectric properties. The Fe-JoFET exhibits significant hysteresis in the switching current and normal-state resistance transfer characteristics, which depend on the range of gate voltages. This phenomenon opens a new research area exploring the interaction between ferroelectricity and superconductivity in hybrid superconducting-semiconducting systems, with potential applications in cryogenic data storage and computation. Supporting this, the Fe-JoFET was operated as a cryogenic superconducting single memory cell, exhibiting both dissipative and non-dissipative states. Its non-volatility was tested over a 24-hour measurement period. We also demonstrated that the Fe-JoFET can retain information at temperatures above the superconductor critical temperature, resulting in a temperature-fault-tolerant memory cell resistant to temperature oscillations or, in the worst case, cryostat faults.

cond-mat.supr-con↗

arXiv2025

Josephson Field Effect Transistors with InAs on Insulator and High Permittivity Gate Dielectrics

InAs on Insulator (InAsOI) has been recently demonstrated as a promising platform to develop hybrid semiconducting-superconducting Josephson Junctions (JJs) and Josephson Field Effect Transistors (JoFETs). The InAsOI consists of an InAs epilayer grown onto a cryogenic-electrically-insulating InAlAs metamorphic buffer, which allows the electrical decoupling of surface-exposed adjacent devices together with a high critical current density integration. The miniaturization of Si microchips has progressed significantly due to the integration of high permittivity (high-k) gate insulators, allowing an increased gate coupling with the transistor channel with consequent reduced gate operating voltages and leakages. As well as for Si-based FETs, integrating high-k gate insulators with JoFETs promises similar advantages in superconducting electronics. Here, we investigate the gate-tunable electrical properties of InAsOI-based JoFETs featuring different high-k gate insulators, namely, HfO2 and Al2O3. We found that both the ungated and gate-tunable electrical properties of the JoFETs are strongly dependent on the insulator chosen. With both dielectrics, the JoFETs can entirely suppress the switching current and increase the normal state resistance by 10-20 times using negative gate voltages. The HfO2-JoFETs exhibit improved gate-tunable electrical performance compared to those achieved with Al2O3-JoFETs, which is related to the higher permittivity of the insulator. Gate-dependent electrical properties of InAsOI-based JoFETs were evaluated in the temperature range from 50 mK to 1 K. Moreover, under the influence of an out-of-plane magnetic field, JoFETs exhibited an unconventional Fraunhofer diffraction pattern, from which an edge-peaked supercurrent density distribution was calculated.

cond-mat.supr-con↗

arXiv2025

Back-action supercurrent diodes

Back-action refers to a response that retro-acts on a system to tailor its properties with respect to an external stimulus. This effect is at the heart of many electronic devices such as amplifiers, oscillators, and sensors. Here, we demonstrate that back-action can be exploited to achieve non-reciprocal transport in superconducting circuits. In our devices, dissipationless current flows in one direction whereas dissipative transport occurs in the opposite direction. Supercurrent diodes presented so far rely on magnetic elements or vortices to mediate charge transport or external magnetic fields to break time-reversal symmetry. Back-action solely turns a conventional reciprocal superconducting weak link with no asymmetry between the current bias directions into a rectifier, where the critical current amplitude depends on the bias sign. The self-interaction of the supercurrent stems from the gate tunability of the critical current in metallic and semiconducting systems, which promotes nearly ideal magnetic field-free rectification with selectable polarity.

cond-mat.mes-hall↗