Quantum Dot-Based Frequency Multiplier

• Published in: PRX quantum Vol. 4; no. 2; p. 020346
• Main Authors: Oakes, G.A., Peri, L., Cochrane, L., Martins, F., Hutin, L., Bertrand, B., Vinet, M., Gomez Saiz, A., Ford, C.J.B., Smith, C.G., Gonzalez-Zalba, M.F.
• Format: Journal Article
• Language: English
• Published: APS Physics 01-06-2023; American Physical Society
• Subjects: Condensed Matter; Physics; Quantum Physics; density; semiconductor; qubit; cryogenics; quantum; nonlinear; computer; silicon; hybrid; performance; quantum dot; temperature; noise; readout
• ISSN: 2691-3399; 2691-3399
• DOI: 10.1103/PRXQuantum.4.020346

Silicon offers the enticing opportunity to integrate hybrid quantum-classical computing systems on a single platform. For qubit control and readout, high-frequency signals are required. Therefore, devices that can facilitate its generation are needed. Here, we present a quantum dot-based radiofrequency multiplier operated at cryogenic temperatures. The device is based on the non-linear capacitance-voltage characteristics of quantum dot systems arising from their low-dimensional density of states. We implement the multiplier in a multi-gate silicon nanowire transistor using two complementary device configurations: a single quantum dot coupled to a charge reservoir and a coupled double quantum dot. We study the harmonic voltage conversion as a function of energy detuning, multiplication factor and harmonic phase noise and find near ideal performance up to a multiplication factor of 10. Our results demonstrate a method for high-frequency conversion that could be readily integrated into silicon-based quantum computing systems and be applied to other semiconductors.