Nearly room temperature ferromagnetism in pressure-induced correlated metallic state of van der Waals insulator CrGeTe$_3$

Dilip Bhoi; Jun Gouchi; Naoka Hiraoka; Yufeng Zhang; Norio Ogita; Takumi Hasegawa; Kentaro Kitagawa; Hidenori Takagi; Kee Hoon Kim; Yoshiya Uwatoko

doi:10.1103/physrevlett.127.217203

arXiv · 2107.10573

Nearly room temperature ferromagnetism in pressure-induced correlated metallic state of van der Waals insulator CrGeTe$_3$

Dilip Bhoi·Jun Gouchi·Naoka Hiraoka·Yufeng Zhang·Norio Ogita·Takumi Hasegawa·Kentaro Kitagawa·Hidenori Takagi·Kee Hoon Kim·Yoshiya Uwatoko

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Abstract

A complex interplay of different energy scales involving Coulomb repulsion, spin-orbit coupling and Hund's coupling energy in two-dimensional (2D) van der Waals (vdW) material produces novel emerging physical state. For instance, ferromagnetism in vdW charge transfer insulator CrGeTe$_3$, that provides a promising platform to simultaneously manipulate the magnetic and electrical properties for potential device implementation using few layers thick materials. Here, we show a continuous tuning of magnetic and electrical properties of CrGeTe$_3$ single crystal using pressure. With application of pressure, CrGeTe$_3$ transforms from a FM insulator with Curie temperature, $T_{\rm{C}} \sim $ 66 K at ambient condition to a correlated 2D Fermi metal with $T_{\rm{C}}$ exceeding $\sim$ 250 K. Notably, absence of an accompanying structural distortion across the insulator-metal transition (IMT) suggests that the pressure induced modification of electronic ground states are driven by electronic correlation furnishing a rare example of bandwidth-controlled IMT in a vdW material.

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Dilip Bhoi, Jun Gouchi, Naoka Hiraoka, Yufeng Zhang, Norio Ogita, Takumi Hasegawa, Kentaro Kitagawa, Hidenori Takagi, Kee Hoon Kim, Yoshiya Uwatoko. 2021-07-22. Nearly room temperature ferromagnetism in pressure-induced correlated metallic state of van der Waals insulator CrGeTe$_3$. https://doi.org/10.1103/physrevlett.127.217203

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