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| Main Authors: | , , , , , , |
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| Format: | Preprint |
| Published: |
2025
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| Subjects: | |
| Online Access: | https://arxiv.org/abs/2501.11056 |
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| _version_ | 1866929681980194816 |
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| author | Kumbhakar, Prasanta Shanmugam, Anusha Mishra, Akhileshwar Pant, Ravi Reno, J L Addamane, S Thalakulam, Madhu |
| author_facet | Kumbhakar, Prasanta Shanmugam, Anusha Mishra, Akhileshwar Pant, Ravi Reno, J L Addamane, S Thalakulam, Madhu |
| contents | Inherent randomness and the resulting stochastic behavior of fundamental particles manifested as quantum noise put a lower bound on measurement imprecision in the quantum measurement process. In addition, the quantum noise imparts decoherence and dephasing to the system being measured, referred to as the measurement back-action. While the microscopic effects of back-action have been observed, macroscopic evidence is a rarity. Here we report a macroscopic display of the back-action of an ultra-sensitive quantum point contact (QPC) electrical amplifier whose transport is defined by the quantum tunneling of electrons. The QPC amplifier, realized on GaAs-AlGaAs heterostructures, coupled to a planar superconducting resonator, operates at a frequency of 2.155 GHz in the shot-noise-limited regime. The shot-noise excitation of the mechanical modes and the resulting piezoelectric polarization enhancing the shot-noise at the mode frequencies form a positive feedback loop between the electrical and mechanical degrees of freedom. While the excitation of the vibrational modes is a display of the macroscopic effects of measurement back-action, the amplitudes of the noise peaks allow us to calibrate the displacement sensitivity of the QPC-resonator systems, which is in the order of 35 fm/SQRT(Hz) range, making it an excellent sensor for ultra-sensitive and fast strain or displacement detection. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2501_11056 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Shot-noise-driven macroscopic vibrations and displacement transduction in quantum tunnel junctions Kumbhakar, Prasanta Shanmugam, Anusha Mishra, Akhileshwar Pant, Ravi Reno, J L Addamane, S Thalakulam, Madhu Mesoscale and Nanoscale Physics Inherent randomness and the resulting stochastic behavior of fundamental particles manifested as quantum noise put a lower bound on measurement imprecision in the quantum measurement process. In addition, the quantum noise imparts decoherence and dephasing to the system being measured, referred to as the measurement back-action. While the microscopic effects of back-action have been observed, macroscopic evidence is a rarity. Here we report a macroscopic display of the back-action of an ultra-sensitive quantum point contact (QPC) electrical amplifier whose transport is defined by the quantum tunneling of electrons. The QPC amplifier, realized on GaAs-AlGaAs heterostructures, coupled to a planar superconducting resonator, operates at a frequency of 2.155 GHz in the shot-noise-limited regime. The shot-noise excitation of the mechanical modes and the resulting piezoelectric polarization enhancing the shot-noise at the mode frequencies form a positive feedback loop between the electrical and mechanical degrees of freedom. While the excitation of the vibrational modes is a display of the macroscopic effects of measurement back-action, the amplitudes of the noise peaks allow us to calibrate the displacement sensitivity of the QPC-resonator systems, which is in the order of 35 fm/SQRT(Hz) range, making it an excellent sensor for ultra-sensitive and fast strain or displacement detection. |
| title | Shot-noise-driven macroscopic vibrations and displacement transduction in quantum tunnel junctions |
| topic | Mesoscale and Nanoscale Physics |
| url | https://arxiv.org/abs/2501.11056 |