Quantum point contact displacement transducer for a mechanical resonator at sub-Kelvin temperatures
- 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, Journal Name: Applied Physics Letters Journal Issue: 19 Vol. 103; ISSN APPLAB; ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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