Broadband Measurement of Quantum Radiation Pressure Noise at Room Temperature

M. J. Yap, J. Cripe, Georgia L. Mansell +8 more

J. Cripe, Robinjeet Singh, Warren W. Johnson +2 more

J. Cripe

Tobias Jan Kippenberg, Vivishek Sudhir, Ryan Schilling +3 more

We report on the observation of quantum correlations developed in a light beam that has interacted with a room-temperature nanomechanical oscillator. The vacuum fluctuations of the light drive the mechanical oscillator via the radiation pressure interaction, so that the phase of the transmitted light carries imprints of its own amplitude. We detect these subtle correlations, at the 5% level, using broadband measurements of the transmitted light in a homodyne detector tuned close to the amplitude quadrature. We also show how such correlations can be used for quantum-enhanced force metrology at room-temperature.

Philipp Haslinger, Matt Jaffe, Victoria Xu +5 more

Objects at finite temperature emit thermal radiation with an outward energy–momentum flow, which exerts an outward radiation pressure. At room temperature, a caesium atom scatters on average less than one of these blackbody radiation photons every 108 years. Thus, it is generally assumed that any scattering force exerted on atoms by such radiation is negligible. However, atoms also interact coherently with the thermal electromagnetic field. In this work, we measure an attractive force induced by blackbody radiation between a caesium atom and a heated, centimetre-sized cylinder, which is orders of magnitude stronger than the outward-directed radiation pressure. Using atom interferometry, we find that this force scales with the fourth power of the cylinder’s temperature. The force is in good agreement with that predicted from an a.c. Stark shift gradient of the atomic ground state in the thermal radiation field 1 . This observed force dominates over both gravity and radiation pressure, and does so for a large temperature range. The effect of blackbody radiation is expected to be very weak. The acceleration due to the attractive optical forces from blackbody radiation is measured in an atom interferometer and, surprisingly, it dominates gravity and radiation pressure

Vivishek Sudhir, R. Schilling, S. A. Fedorov +3 more

When light reflects off a mirror, its intensity and phase become quantum correlated as a result of radiation pressure. These correlations could be used to erase quantum backaction, which poses a fundamental limit to the precision of interferometric displacement measurements. For the first time, these correlations are observed and exploited in a room-temperature interferometer, which could lead to advances in quantum-enhanced metrology.