A terahertz-driven non-equilibrium phase transition in a room temperature atomic vapour

Wade, C.G.; Marcuzzi, M.; Levi, E.; Kondo, J.M.; Lesanovsky, I.; Adams, C.S.; Weatherill, K.J.

Abstract

There are few demonstrated examples of phase transitions that may be driven directly by terahertz frequency electric fields, and those that are known require field strengths exceeding 1 MV cm−1. Here we report a non-equilibrium phase transition driven by a weak (≪1 V cm−1), continuous-wave terahertz electric field. The system consists of room temperature caesium vapour under continuous optical excitation to a high-lying Rydberg state, which is resonantly coupled to a nearby level by the terahertz electric field. We use a simple model to understand the underlying physical behaviour, and we demonstrate two protocols to exploit the phase transition as a narrowband terahertz detector: the first with a fast (20 μs) non linear response to nano-Watts of incident radiation, and the second with a linearised response and effective noise equivalent power ≤1 pW Hz−1/2. The work opens the door to a class of terahertz devices controlled with low-field intensities and operating in a room temperature environment.

Citation

Wade, C., Marcuzzi, M., Levi, E., Kondo, J., Lesanovsky, I., Adams, C., & Weatherill, K. (2018). A terahertz-driven non-equilibrium phase transition in a room temperature atomic vapour. Nature Communications, 9, 1-7. https://doi.org/10.1038/s41467-018-05597-4

• Journal Article Type: Article
• Acceptance Date: Jul 16, 2018
• Online Publication Date: Sep 3, 2018
• Publication Date: Sep 3, 2018
• Deposit Date: Aug 27, 2018
• Publicly Available Date: Sep 3, 2018
• Journal: Nature Communications
• Electronic ISSN: 2041-1723
• Publisher: Nature Publishing Group
• Peer Reviewed: Peer Reviewed
• Volume: 9
• Article Number: 3567
• Pages: 1-7
• DOI: https://doi.org/10.1038/s41467-018-05597-4
• Public URL: https://nottingham-repository.worktribe.com/output/1038780
• Publisher URL: https://www.nature.com/articles/s41467-018-05597-4
• Contract Date: Sep 3, 2018