Abstract Superconductor nanodevices serve significant platforms for solid-state quantum systems, such as quantum computer and quantum detector. And the out-of-equilibrium phenomena always plays an important role in superconductor nanodevices. Here we reported an incoherent superconducting nanowire phonon detector for revealing the out-of-equilibrium phenomena in the controversial gate-controlled superconductivity (GCS), which recently provide a new perspective on the design of superconducting devices. The asymmetric dependence of the gate-inducing signal count rate (CR) on the gate voltage polarity not only suggests that GCS is dominated by the hybrid effect of field-emission electrons and the out-of-equilibrium phonons, but also verifies the capability of the detector to respond to phonons. These conclusions are further proven by applying opposite gate voltages on two remote gates, in which only phonons play a role and the asymmetry vanishes. We show the significance of nanowire sensitivity and band structure to GCS, which can be used to modulate the polarity symmetry of CR on gate voltage. Proposed detector contributes to the research on the out-of-equilibrium phenomena and has potential in constructing phonon-based solid quantum devices.
Abstract Superconductor nanodevices serve significant platforms for solid-state quantum systems, such as quantum computer and quantum detector. And the out-of-equilibrium phenomena always plays an important role in superconductor nanodevices. Here we reported an incoherent superconducting nanowire phonon detector for revealing the out-of-equilibrium phenomena in the controversial gate-controlled superconductivity (GCS), which recently provide a new perspective on the design of superconducting devices. The asymmetric dependence of the gate-inducing signal count rate (CR) on the gate voltage polarity not only suggests that GCS is dominated by the hybrid effect of field-emission electrons and the out-of-equilibrium phonons, but also verifies the capability of the detector to respond to phonons. These conclusions are further proven by applying opposite gate voltages on two remote gates, in which only phonons play a role and the asymmetry vanishes. We show the significance of nanowire sensitivity and band structure to GCS, which can be used to modulate the polarity symmetry of CR on gate voltage. Proposed detector contributes to the research on the out-of-equilibrium phenomena and has potential in constructing phonon-based solid quantum devices.
Superconductor nanodevices are widely applied in quantum computers and quantum detectors. Gate-controlled supercurrent (GCS) provides a potential platform for developing quantum systems, but the mechanism remains controversial. Recent reports suggest that there may be out-of-equilibrium phonons acting in GCS, but insightful investigations are lacking. Here, we report an incoherent superconducting nanowire phonon detector to convert the phase transitions induced by out-of-equilibrium phonons into electric pulse signals, enabling discrete-time measurements. The statistical properties of the gate-induced signals reveal the Poisson properties of phonon injection and the thermalization dynamics of hot electrons in the GCS on the α-Si substrate. These mechanisms are further evidenced by applying opposite gate voltages on two remote gates, in which only phonons play a role. The proposed detector not only is a candidate for constructing phonon-based solid quantum devices based on the GCS but also contributes to research on the out-of-equilibrium phenomena in superconducting nanodevices.
The interplay of alternative materials, large-scale integration technologies, and innovative devices plays a pivotal role on the way to fault-tolerant quantum computing. In this context, gate-controlled superconductivity (GCS) emerges as a key enabling technology, promising to advance superconducting logic and quantum electronics, complementing conventional approaches based on Josephson effects and quantum interference. Here, we demonstrate all-metallic superconducting ZrN nanostructures on silicon, fabricated entirely using a subtractive, monolithic dry-etch approach with a 300 mm CMOS-compatible process flow. For Dayem-bridge weak links with decreasing width down to 27 nm, we observe Tc of 7.3 K, width-dependent switching characteristics, and a progressive approach of the tunneling limit. In laterally gated Dayem-bridge and nanowire devices, we observe GCS with full suppression of the critical current, where required gate voltages <5 V promise compatibility with CMOS interfaces. Asymmetries in polarity-dependent power injection via field emission support GCS models that attribute the effect to quasiparticle relaxation through phonon emission. Additional asymmetries in the GCS effect suggest an influence of the substrate condition after dry etching. Field emission features in the gated nanowire device imply superimposed current paths along the gate edge and corners. Finally, we analyze magnetic interference in Dayem-bridge weak links and superconducting quantum interference devices, where quantum interference is governed by Josephson effects and inductance loop asymmetries. Our results contribute to the scaling efforts in hybrid superconducting electronics and quantum-processing units.
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.
It was recently discovered that supercurrents flowing through thin superconducting nanowires can be quenched by applying a gate voltage to a nearby gate electrode. This gate control of supercurrents, known as the GCS effect, could enable superconducting transistor logic. Here, we report that the GCS also manifests in a suppression of Meissner screening, establishing the phenomenon as a genuine feature of superconductivity that is not restricted to transport. Using a scanning nitrogen-vacancy (NV) magnetometer at sub-Kelvin temperatures, we image the nanoscale spatial region of GCS suppression in micron-size niobium islands. Our observations are compatible with a microscopic hot-spot model of quasiparticle generation and diffusion, and in conflict with other candidate mechanisms such as Joule heating or an electric field effect. Our work introduces an alternative means for studying quasiparticle dynamics in superconducting nanostructures, and showcases the power of local imaging techniques for understanding emergent condensed matter phenomena.
It was recently discovered that supercurrents flowing through thin superconducting nanowires can be quenched by a gate voltage. This gate control of supercurrents, known as the GCS effect, could enable superconducting transistor logic. Here, we report that the GCS also manifests in a suppression of Meissner screening, establishing the phenomenon as a genuine feature of superconductivity that is not restricted to transport. Using a scanning nitrogen-vacancy magnetometer at sub-Kelvin temperatures, we image the nanoscale spatial region of GCS suppression in micron-size niobium islands. Our observations are compatible with a microscopic hot-spot model of quasiparticle generation and diffusion, and in conflict with other candidate mechanisms such as Joule heating or an electric field effect. Our work introduces an alternative means for studying quasiparticle dynamics in superconducting nanostructures, and showcases the power of local imaging techniques for understanding emergent condensed matter phenomena.
Superconducting nanowires are widely used in quantum computing, superconducting electronics, and low-temperature physics due to their high sensitivity, compact footprint, and low noise. Here, we present a gate-tunable superconducting nanowire thermometer that enables high-precision temperature measurements in the liquid-helium regime by applying a gate voltage. Experimental results demonstrate stable operation in the 2.5-6.2 K range, with a maximum sensitivity of 4.51×105 cps/K, indicating the potential for sub-millikelvin resolution. The device further exhibits a minimum noise-equivalent temperature difference (NETD) of 5.5 mK, corresponding to millikelvin-level measurement accuracy. Its on-chip integrability, fast response, and tunable performance make it a promising solution for low-temperature sensing and on-chip thermal monitoring in quantum chips. This work provides an experimental platform and theoretical basis for electric-field-controlled superconducting electronics and highlights the potential of gate-controlled nanowires for integrated cryogenic sensing technologies.