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

DOI: 10.1002/adma.202109144

Authors: Suhan Son (Seoul National University) , Youjin Lee (Seoul National University) , Jae Ha Kim (Yonsei University) , Beom Hyun Kim (Korea Institute for Advanced Study) , Chaebin Kim (Seoul National University) , Woongki Na (Sogang University) , Hwiin Ju (Gwangju Institute of Science and Technology (GIST)) , Sudong Park (Pohang University of Science and Technology; MPPHC-CPM, Max Planck POSTECH/Korea Research Initiative) , Abhishek Nag (Diamond Light Source) , Ke-Jin Zhou (Diamond Light Source) , Young-Woo Son (Korea Institute for Advanced Study) , Hyeongdo Kim (Pohang Accelerator Laboratory) , Woo-Suk Noh (MPPHC-CPM, Max Planck POSTECH/Korea Research Initiative) , Jae-Hoon Park (ohang University of Science and Technology; MPPHC-CPM, Max Planck POSTECH/Korea Research Initiative) , Jong Seok Lee (Gwangju Institute of Science and Technology (GIST)) , Hyeonsik Cheong (Sogang University) , Jae Hoon Kim (Yonsei University) , Je-Geun Park (Seoul National University; Institute for Basic Science (IBS))
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Advanced Materials

State: Published (Approved)
Published: December 2021
Diamond Proposal Number(s): 29554

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.

Journal Keywords: multiferroic van der Waals NiI2; Zhang-Rice triplet; Zhang-Rice singlet; quantum entanglement; Resonant x-ray scattering; second harmonic generation; optical absorption; many- body calculation

Diamond Keywords: Ferromagnetism; Ferroelectricity

Subject Areas: Materials, Physics


Instruments: I21-Resonant Inelastic X-ray Scattering (RIXS)

Added On: 28/12/2021 10:50

Discipline Tags:

Quantum Materials Hard condensed matter - electronic properties Multiferroics Physics Magnetism Materials Science

Technical Tags:

Scattering Resonant Inelastic X-ray Scattering (RIXS)