We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Coherent momentum control of forbidden excitons.
- Authors
Ma, Xuezhi; Kudtarkar, Kaushik; Chen, Yixin; Cunha, Preston; Ma, Yuan; Watanabe, Kenji; Taniguchi, Takashi; Qian, Xiaofeng; Hipwell, M. Cynthia; Wong, Zi Jing; Lan, Shoufeng
- Abstract
A double-edged sword in two-dimensional material science and technology is optically forbidden dark exciton. On the one hand, it is fascinating for condensed matter physics, quantum information processing, and optoelectronics due to its long lifetime. On the other hand, it is notorious for being optically inaccessible from both excitation and detection standpoints. Here, we provide an efficient and low-loss solution to the dilemma by reintroducing photonics bound states in the continuum (BICs) to manipulate dark excitons in the momentum space. In a monolayer tungsten diselenide under normal incidence, we demonstrated a giant enhancement (~1400) for dark excitons enabled by transverse magnetic BICs with intrinsic out-of-plane electric fields. By further employing widely tunable Friedrich-Wintgen BICs, we demonstrated highly directional emission from the dark excitons with a divergence angle of merely 7°. We found that the directional emission is coherent at room temperature, unambiguously shown in polarization analyses and interference measurements. Therefore, the BICs reintroduced as a momentum-space photonic environment could be an intriguing platform to reshape and redefine light-matter interactions in nearby quantum materials, such as low-dimensional materials, otherwise challenging or even impossible to achieve. Here, the authors integrate a photonic crystal, supporting photonic bound states in the continuum (BICs), with monolayer WSe2, and leverage the high energy confinement of the BIC modes to demonstrate coherent directional dark exciton emission.
- Subjects
CONDENSED matter physics; EXCITON theory; MATERIALS science; MOMENTUM space; BOUND states
- Publication
Nature Communications, 2022, Vol 13, Issue 1, p1
- ISSN
2041-1723
- Publication type
Article
- DOI
10.1038/s41467-022-34740-5