Abstract
Nonlinear interferometers that replace beam splitters in Mach-Zehnder interferometers with nonlinear amplifiers for quantum-enhanced phase measurements have drawn increasing interest in recent years, but practical quantum sensors based on nonlinear interferometry remain an outstanding challenge. Here, we demonstrate the first practical application of nonlinear interferometry by measuring the displacement of an atomic force microscope microcantilever with quantum noise reduction of up to 3 dB below the standard quantum limit, corresponding to a quantum-enhanced measurement of beam displacement of 1.7 fm/Hz. Further, we minimize photon backaction noise while taking advantage of quantum noise reduction by transducing the cantilever displacement signal with a weak squeezed state while using dual homodyne detection with a higher power local oscillator. This approach may enable quantum-enhanced broadband, high-speed scanning probe microscopy.
| Original language | English |
|---|---|
| Article number | 230504 |
| Journal | Physical Review Letters |
| Volume | 124 |
| Issue number | 23 |
| DOIs | |
| State | Published - Jun 12 2020 |
Funding
This research was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. The experimental concept was conceived and initial experiments were performed as part of the Laboratory-Directed Research and Development Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC for the U.S. Department of Energy. N. S., E. B., and J. B. were supported by the U.S. Department of Energy, Office of Science, Office of Workforce Development for Teachers and Scientists (WDTS) under the Science Undergraduate Laboratory Internship program. J. G. was supported by the W. M. Keck Foundation. This research was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. The experimental concept was conceived and initial experiments were performed as part of the Laboratory-Directed Research and Development Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC for the U.S. Department of Energy. N. S., E. B., and J. B. were supported by the U.S. Department of Energy, Office of Science, Office of Workforce Development for Teachers and Scientists (WDTS) under the Science Undergraduate Laboratory Internship program. J. G. was supported by the W. M. Keck Foundation.
| Funders | Funder number |
|---|---|
| Office of Workforce Development for Teachers | |
| UT-Battelle | |
| U.S. Department of Energy | |
| W. M. Keck Foundation | |
| Office of Science | |
| Basic Energy Sciences | |
| Workforce Development for Teachers and Scientists | |
| Oak Ridge National Laboratory | |
| Division of Materials Sciences and Engineering |