Abstract
We present a proposal for a tunable source of single photons operating in the terahertz (THz) regime. This scheme transforms incident visible photons into quantum THz radiation by driving a single polar quantum emitter with an optical laser, with its permanent dipole enabling dressed THz transitions enhanced by the resonant coupling to a cavity. This mechanism offers optical tunability of properties such as the frequency of the emission or its quantum statistics (ranging from antibunching to entangled multiphoton states) by modifying the intensity and frequency of the drive. We show that the implementation of this proposal is feasible with state-of-the-art photonics technology.
- Received 30 May 2023
- Revised 19 October 2023
- Accepted 5 December 2023
DOI:https://doi.org/10.1103/PRXQuantum.5.010312
Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.
Published by the American Physical Society
Physics Subject Headings (PhySH)
Popular Summary
Sources of single particles of light (photons) in the terahertz (THz) frequency range have not yet been attained. An important challenge is that the usual approach of generating single photons via spontaneous emission is not efficient when using a THz quantum emitter. We propose an alternative to make a powerful source of single photons in the THz range.
Our idea involves using a polar quantum emitter with an optical transition frequency driven by an optical laser, which is placed inside a cavity designed to contain THz light. Importantly, the photons from the laser hybridize with the emitter, creating new atomic transitions that are separated by THz frequencies. The cavity can then efficiently extract photons from deexcitations along these transitions, provided the emitter is polar. We show how this system can produce light with unique quantum properties, such as antibunching, which means the light particles are emitted one at a time instead of in groups. Furthermore, this system can be easily adjusted to emit light at different frequencies and with a plethora of quantum properties by changing the frequency or strength of the laser that drives it.
This flexibility allows us to switch between emitting single photons or multiple correlated photons, making our idea a versatile source of quantum light, a significant step toward making THz quantum optics a reality.
