APS March Meeting 2020
Volume 65, Number 1
Monday–Friday, March 2–6, 2020;
Denver, Colorado
Session L62: Electron Transport in Nanostructures I
8:00 AM–11:00 AM,
Wednesday, March 4, 2020
Room: Mile High Ballroom 4C
Sponsoring
Unit:
DMP
Chair: Jia Li, Brown University
Abstract: L62.00001 : Ultrafast and Cooperative Light-Matter Coupling
Abstract
Presenter:
Junichiro Kono
(Rice Univ)
Author:
Junichiro Kono
(Rice Univ)
Recent experiments have shown that light and matter can mix together to an extreme degree, entering previously uncharted regimes of light-matter interactions [1]. This talk will summarize a series of experiments we have performed in such regimes. We will first describe our observation of ultrastrong coupling (USC) of a 2D electron gas with high-Q THz cavity photons in a quantizing magnetic field, demonstrating a record-high cooperativity [2]. The electron cyclotron resonance peak exhibited splitting into the lower and upper polariton branches with a magnitude that is proportional to the square-root of the electron density, a hallmark of cooperative vacuum Rabi splitting (VRS), known as Dicke cooperativity. Additionally, we have obtained evidence for the vacuum Bloch-Siegert shift [3], a signature of the breakdown of the rotating-wave approximation. The second part of this talk will present microcavity exciton polaritons in a thin film of aligned carbon nanotubes [4] embedded in a Fabry-Pérot cavity. This system exhibited cooperative USC with unusual continuous controllability over the coupling strength through polarization rotation [5]. Finally, we have generalized the concept of Dicke cooperativity to show that it also occurs in a magnetic solid in the form of matter-matter interaction [6]. Specifically, the exchange interaction of N paramagnetic Er3+ spins with an Fe3+ magnon field in ErFeO3 exhibited a VRS whose magnitude is proportional to N1/2. Our results provide a route for understanding, controlling, and predicting novel phases of condensed matter using concepts and tools available in quantum optics. 1. P. Forn-Díaz, L. Lamata, E. Rico, J. Kono, and E. Solano, Revi. Mod. Phys. 91, 025005 (2019). 2. Q. Zhang et al., Nat. Phys. 12, 1005 (2016). 3. X. Li et al., Nat. Photon. 12, 324 (2018). 4. X. He et al., Nat. Nanotechnol. 11, 633 (2016). 5. W. Gao et al., Nat. Photon. 12, 362 (2018). 6. X. Li et al., Science 361, 794 (2018).