Nanowerk February 14, 2022
Quantum microscopy relies on extremely delicate control of light waves. However, its sensitivity is typically limited by optical losses. A team of researchers in the US (Oak Ridge National Laboratory, Tulane University, MIT, University of Colorado) circumvented the problem with an entangled light called squeezed light, that is, the intensities of the light beams are correlated with each other at the quantum level resulting in noise reduction of up to 3 dB below the standard quantum limit. They minimized the 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. The approach can unveil fast electronic interactions that cannot be measured with a classical microscope. In addition, the squeezed light heats the microscope much less than a laser would. According to the researchers this approach may enable quantum-enhanced broadband, high-speed scanning probe microscopy…read more. TECHNICAL ARTICLE
An acousto-optic modulator (AOM) redshifts the probe 3.042 GHz from the pump… Credit: Phys. Rev. Lett. 124, 230504, 12 June 2020