Quantum point contact displacement transducer for a mechanical resonator at sub-Kelvin temperatures

Journal Article · Mon Nov 04 00:00:00 EST 2013 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4828890· OSTI ID:22224084

Okazaki, Yuma; Mahboob, Imran; Onomitsu, Koji; Sasaki, Satoshi; Yamaguchi, Hiroshi ^[1]

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1. NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198 (Japan)

Highly sensitive displacement transduction of a 1.67 MHz mechanical resonator with a quantum point contact (QPC) formed in a GaAs heterostructure is demonstrated. By positioning the QPC at the point of maximum mechanical strain on the resonator and operating at 80 mK, a displacement responsivity of 3.81 A/m is measured, which represents a two order of magnitude improvement on the previous QPC based devices. By further analyzing the QPC transport characteristics, a sub-Poisson-noise-limited displacement sensitivity of 25 fm/Hz{sup 1/2} is determined which corresponds to a position resolution that is 23 times the standard quantum limit.

• OSTI ID: 22224084
• Journal Information: Applied Physics Letters, Vol. 103, Issue 19; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ELECTRIC CONTACTS
GALLIUM ARSENIDES
MHZ RANGE 01-100
NOISE
PIEZOELECTRICITY
POSITIONING
RESOLUTION
RESONATORS
SENSITIVITY
STRAINS
TRANSDUCERS