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arXiv · 2609.34536

Magneto-optical Kerr spectroscopy of exciton Rydberg states in a magnetic van der Waals heterostructure

Astha Khandelwal·Benran Zhang·Madhusmita Jena·Zhenchao Wen·Kenji Watanabe·Takashi Taniguchi·Saroj P. Dash·Zhenglu Li·Ryo Kitaura·Bhagwati Prasad·Daichi Kozawa
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Abstract

Excitonic states in two-dimensional semiconductors are sensitive to time-reversal symmetry breaking, yet how interfacial exchange acts on higher-lying exciton Rydberg states remains largely unexplored. Here we show that wavelength-resolved magneto-optical Kerr spectroscopy of a proximity-coupled MoSe$_2$/Fe$_3$GaTe$_2$ van der Waals heterostructure resolves magnetic symmetry breaking across the A- and B-exciton manifolds. Combining reflection, photoluminescence, and photoluminescence excitation spectroscopy with first-principles many-body calculations including screening by the metallic Fe$_3$GaTe$_2$ layer, we assign the strongly enhanced Kerr resonances to the ground and 2s states of both manifolds. Reversing the magnetic field inverts the polarity of every resonance. A field-odd/field-even decomposition confirms a magnetic origin. The opposite Kerr polarities of the A- and B-exciton manifolds can be explained by proximity-induced exchange coupling to the opposite valence-band spins of the two exciton series. Our results establish resonant Kerr spectroscopy as a sensitive probe of magnetically induced symmetry breaking across the excitonic manifold.

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Astha Khandelwal, Benran Zhang, Madhusmita Jena, Zhenchao Wen, Kenji Watanabe, Takashi Taniguchi, Saroj P. Dash, Zhenglu Li, Ryo Kitaura, Bhagwati Prasad, Daichi Kozawa. 2026-09-28. Magneto-optical Kerr spectroscopy of exciton Rydberg states in a magnetic van der Waals heterostructure. https://arxiv.org/abs/2609.34536

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