Frequency-dressing a stream of single photons with preserved coherence
Uttam Paudel, A. P. Burgers, Michael K. Yakes, Allan S. Bracker, D. Gammon, Duncan G. Steel · arXiv (Cornell University) · 2017
Generation and manipulation of the quantum state of a single photon is at the heart of many quantum information protocols. It has been experimentally shown that the temporal profile of a single photon can be post-modified through time-gated modulation techniques. Similarly, the frequency of a single photon can be changed with parametric processes. In this paper, we have used an electro-optic phase modulator to arbitrarily dress the spectrum of a single photon packet emitted by a quantum dot and to generate new frequency components (modes) where the new modes have well-defined phases relative to the central mode. Through two-photon interference measurements, we show that for an output consisting of three modes (the original mode and two side bands on either side) the second-order coherence of the single photon is well-preserved. The sideband generation technique can be employed to generate a frequency qubit or qutrit out of a single photon and also for encoding information in the frequency sidebands for quantum cryptography.