Nanodevices for Quantum Computing Using Photons

Christophe Couteau

J.C. Gallop, L. Hao

This article reviews recent progress in superconducting nanodevices, with particular emphasis on fabrication methods developed for superconducting nanowires and nanoscale Josephson junctions based on different barrier materials. It evaluates the future potential of superconducting nanodevices, including nano-superconducting quantum interference devices (nanoSQUIDs), in light of improvements in nanoscale fabrication and manipulation techniques, along with their likely impacts on future quantum technology and measurement. The article first considers efforts to realize devices at the physical scale of 100 nm and below before discussing different types of Josephson junction such as trilayer junctions. It also describes the use of focused ion beam milling and electron beam lithography techniques for junction fabrication at the nanoscale and the improved energy sensitivity detectable with a nanoSQUID. Finally, it looks at a range of applications for nanoSQUIDs, superconducting single photon detectors, and other superconducting nanodevices.

Ahmed El-Halawany, Michael Leuenberger

Alberto Politi

Amir H. Safavi‐Naeini

S. Moskal, S. Bednarek, Janusz Adamowski

Abstract: We discuss a possible realization of a quantum controlled-NOT gate with the use of two coupled quantum dots. Transitions between quantum states of a computational basis are driven by the microwave pi-pulse. The parameters of the proposed nanodevice have been optimized in order to make the operation cycle of the gate as short as possible. Numerical solutions of the time-dependent Schrödinger equation allow us to simulate transitions between the quantum states which correspond to the subsequent stages of the gate’s operation. The performed time-dependent simulations are a test of realizability of the quantum controlled-NOT gate in the nanodevice.