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DOE OSTI · 2571896

Quantum confining excitons with an electrostatic moiré superlattice

Gu, Liuxin [University of Maryland, College Park, MD (United States)]·Zhang, Lifu [University of Maryland, College Park, MD (United States)]·Felsenfeld, Sam [University of Maryland, College Park, MD (United States)]·Gao, Beini [University of Maryland, College Park, MD (United States)]·Ma, Rundong [University of Maryland, College Park, MD (United States)]·Park, Suji [Brookhaven National Laboratory (BNL), Upton, NY (United States)]·Jang, Houk [Brookhaven National Laboratory (BNL), Upton, NY (United States)]·Taniguchi, Takashi [National Institute for Materials Science, Tsukuba (Japan)]·Watanabe, Kenji [National Institute for Materials Science, Tsukuba (Japan)]·Zhou, You [University of Maryland, College Park, MD (United States)]
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Abstract

Quantum confining excitons has been a persistent challenge in the pursuit of strong exciton interactions and quantum light generation. Unlike electrons, which can be readily controlled via electric fields, imposing strong nanoscale potentials on excitons to enable quantum confinement has proven challenging. In this study, we utilize piezoelectric force microscopy to image the domain structures of twisted hexagonal boron nitride (h – BN), revealing evidence of strong in-plane electric fields at the domain boundaries. By placing a monolayer MoSe 2 only one to two nanometers away from the twisted h – BN interface, we observe energy splitting of neutral excitons and Fermi polarons by several millielectronvolts at the moiré domain boundaries. By directly correlating local structural and optical properties, we attribute such observations to excitons confined in a nanoscale one-dimensional electrostatic potential created by the strong in-plane electric fields at the moiré domain boundaries. Intriguingly, this 1D quantum confinement results in pronounced polarization anisotropy in the excitons’ reflection and emission, persistent to temperatures as high as ~80 Kelvins. Furthermore, these findings open new avenues for exploring and controlling strongly interacting excitons for classical and quantum optoelectronics.

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2-dimensional systems36 MATERIALS SCIENCEExcitonsQuantum wiresTransition metal dichalcogenidesTwisted heterostructures

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Gu, Liuxin [University of Maryland, College Park, MD (United States)], Zhang, Lifu [University of Maryland, College Park, MD (United States)], Felsenfeld, Sam [University of Maryland, College Park, MD (United States)], Gao, Beini [University of Maryland, College Park, MD (United States)], Ma, Rundong [University of Maryland, College Park, MD (United States)], Park, Suji [Brookhaven National Laboratory (BNL), Upton, NY (United States)], Jang, Houk [Brookhaven National Laboratory (BNL), Upton, NY (United States)], Taniguchi, Takashi [National Institute for Materials Science, Tsukuba (Japan)], Watanabe, Kenji [National Institute for Materials Science, Tsukuba (Japan)], Zhou, You [University of Maryland, College Park, MD (United States)]. 2025-07-08. Quantum confining excitons with an electrostatic moiré superlattice. https://doi.org/10.1103/tyr4-9z16

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