Bottom-up superconducting and Josephson junction devices inside a group-IV semiconductor

Abstract

Superconducting circuits are exceptionally flexible, enabling many different devices from sensors to quantum computers. Separately, epitaxial semiconductor devices such as spin qubits in silicon offer more limited device variation but extraordinary quantum properties for a solid-state system. It might be possible to merge the two approaches, making single-crystal superconducting devices out of a semiconductor by utilizing the latest atomistic fabrication techniques. Here we propose superconducting devices made from precision hole-doped regions within a silicon (or germanium) single crystal. We analyse the properties of this superconducting semiconductor and show that practical superconducting wires, Josephson tunnel junctions or weak links, superconducting quantum interference devices (SQUIDs) and qubits are feasible. This work motivates the pursuit of 'bottom-up' superconductivity for improved or fundamentally different technology and physics.

Brillouin-scattering-induced transparency and non-reciprocal light storage

“…(b) The triply resonant configuration can greatly enhance the Brillouin scattering, thereby reducing the power consumptions 15 17 . (c) Phase matching for the travelling waves enables non-reciprocal optical processes, thus offering potential application in an all-optical integrated isolator and circulator devices 29 30 . Our studies pave the way towards the coherent coupling between photons and acoustic phonons and should stimulate further investigations of non-reciprocity and memory at the quantum level.…”

Superconducting-Semiconductor Quantum Devices: From Qubits to Particle Detectors

“…In this section, we refine the estimation of SC characteristic parameters from [8]. We start with only experimental data and assumptions that the holes can be described by free electron like energy dispersion and that it is a Bardeen-Cooper-Schrieffer (BCS) [21] superconductor in dirty local limit.…”

“…The more recent experiments in silicon are of significant interest as they show highly uniform, highly predictable superconductivity (versus density), while still maintaining the expitaxial nature of the crystal [5]. With respect to device physics, a recent proposal has raised the possibility of using novel material preparation and atomistic fabrication techniques [6], [7] to realize superconducting (SC) devices in purified silicon crystals [8].…”

“…This STM lithography technique (combined with atomic layer doping) has been used only for electron doping so far, reaching very high density of electrons, up to one in four crystal atoms replaced with a dopant [18]. There is high motivation to extend this technique for acceptor doping [8], [19].…”

Silicon superconducting quantum interference device

“…In addition, the quality of the underlying material must also be addressed as it can be an important source of decoherence for quantum devices [11]. In that quest, superconducting boron doped silicon discovered in 2006 [12], can address all of these challenges at once as silicon technology is by far the most mature one for nanoelectronics and for which extremely high quality material can be used [13]. Moreover, the relatively high normal state resistivity of boron doped silicon allows using this material for Microwave Kinetic Inductance Detection [14].As a first step towards superconducting silicon based quantum engineering, we have fabricated a SQUID (Superconducting Quantum Interference Device) from a single layer of superconducting silicon.…”