Twist-tailoring Coulomb correlations in van der Waals homobilayers

Merkl P, Mooshammer F, Brem S, Girnghuber A, Lin KQ, Weigl L, Liebich M, Yong CK, Gillen R, Maultzsch J, Lupton JM, Malic E, Huber R (2020)

Publication Type: Journal article

Publication year: 2020


Book Volume: 11

Article Number: 2167

Journal Issue: 1

DOI: 10.1038/s41467-020-16069-z


The recent discovery of artificial phase transitions induced by stacking monolayer materials at magic twist angles represents a paradigm shift for solid state physics. Twist-induced changes of the single-particle band structure have been studied extensively, yet a precise understanding of the underlying Coulomb correlations has remained challenging. Here we reveal in experiment and theory, how the twist angle alone affects the Coulomb-induced internal structure and mutual interactions of excitons. In homobilayers of WSe2, we trace the internal 1s–2p resonance of excitons with phase-locked mid-infrared pulses as a function of the twist angle. Remarkably, the exciton binding energy is renormalized by up to a factor of two, their lifetime exhibits an enhancement by more than an order of magnitude, and the exciton-exciton interaction is widely tunable. Our work opens the possibility of tailoring quasiparticles in search of unexplored phases of matter in a broad range of van der Waals heterostructures.

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Merkl, P., Mooshammer, F., Brem, S., Girnghuber, A., Lin, K.Q., Weigl, L.,... Huber, R. (2020). Twist-tailoring Coulomb correlations in van der Waals homobilayers. Nature Communications, 11(1).


Merkl, Philipp, et al. "Twist-tailoring Coulomb correlations in van der Waals homobilayers." Nature Communications 11.1 (2020).

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