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arXiv · 2112.11692

Multiferroic-enabled magnetic exciton in 2D quantum entangled van der Waals antiferromagnet NiI2

Suhan Son·Youjin Lee·Jae Ha Kim·Beom Hyun Kim·Chaebin Kim·Woongki Na·Hwiin Ju·Sudong Park·Abhishek Nag·Ke-Jin Zhou·Young-Woo Son·Hyeongdo Kim·Woo-Suk Noh·Jae-Hoon Park·Jong Seok Lee·Hyeonsik Cheong·Jae Hoon Kim·Je-Geun Park
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Abstract

Matter-light interaction is at the center of diverse research fields from quantum optics to condensed matter physics, opening new fields like laser physics. A magnetic exciton is one such rare example found in magnetic insulators. However, it is relatively rare to observe that external variables control matter-light interaction. Here, we report that the broken inversion symmetry of multiferroicity can act as an external knob enabling the magnetic exciton in van der Waals antiferromagnet NiI2. We further discover that this magnetic exciton arises from a transition between Zhang-Rice-triplet and Zhang-Rice-singlet's fundamentally quantum entangled states. This quantum entanglement produces an ultra-sharp optical exciton peak at 1.384 eV with a 5 meV linewidth. Our work demonstrates that NiI2 is two-dimensional magnetically ordered with an intrinsically quantum entangled ground state.

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Suhan Son, Youjin Lee, Jae Ha Kim, Beom Hyun Kim, Chaebin Kim, Woongki Na, Hwiin Ju, Sudong Park, Abhishek Nag, Ke-Jin Zhou, Young-Woo Son, Hyeongdo Kim, Woo-Suk Noh, Jae-Hoon Park, Jong Seok Lee, Hyeonsik Cheong, Jae Hoon Kim, Je-Geun Park. 2021-12-22. Multiferroic-enabled magnetic exciton in 2D quantum entangled van der Waals antiferromagnet NiI2. https://arxiv.org/abs/2112.11692

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