Reading today…

Reading today…

Relativistic and QED Effects in the Fundamental Vibration of T2

T. Madhu Trivikram, M. Schlösser, W. Ubachs, and E. J. Salumbides

Phys. Rev. Lett. 120, 163002 – Published 16 April 2018

The hydrogen molecule has become a test ground for quantum electrodynamical calculations in molecules. Expanding beyond studies on stable hydrogenic species to the heavier radioactive tritium-bearing molecules, we report on a measurement of the fundamental T2 vibrational splitting (v=01) for J=05 rotational levels. Precision frequency metrology is performed with high-resolution coherent anti-Stokes Raman spectroscopy at an experimental uncertainty of 10–12 MHz, where sub-Doppler saturation features are exploited for the strongest transition. The achieved accuracy corresponds to a 50-fold improvement over a previous measurement, and it allows for the extraction of relativistic and QED contributions to T2 transition energies.

Reducing noise in a Raman quantum memory

Reducing noise in a Raman quantum memory

New paper in Optics Letters:

Reducing noise in a Raman quantum memory

https://doi.org/10.1364/OL.41.005055

Optical quantum memories are an important component of future optical and hybrid quantum technologies. Raman schemes are strong candidates for use with ultrashort optical pulses due to their broad bandwidth; however, the elimination of deleterious four-wave mixing noise from Raman memories is critical for practical applications. Here, we demonstrate a quantum memory using the rotational states of hydrogen molecules at room temperature. Polarization selection rules prohibit four-wave mixing, allowing the storage and retrieval of attenuated coherent states with a mean photon number 0.9 and a pulse duration 175 fs. The 1/𝑒 memory lifetime is 85.5 ps, demonstrating a time-bandwidth product of 480 in a memory that is well suited for use with broadband heralded down-conversion and fiber-based photon sources.