Fermi surface reconstruction under pressure in the kagome metal <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>CsV</mml:mi> <mml:mn>3</mml:mn> </mml:msub> <mml:msub> <mml:mi>Sb</mml:mi> <mml:mn>5</mml:mn> </mml:msub> </mml:mrow> </mml:math>

Abstract

This work presents the evolution of the electronic properties of kagome superconductor ${\mathrm{CsV}}_{3}{\mathrm{Sb}}_{5}$ under pressure. The magnetoresistance under high fields of 43 T showed clear Shubnikov--de Haas (SdH) oscillations with multiple frequencies up to 2000 T. With the application of pressure, we observed a sudden change in SdH oscillations with the disappearance of the high-frequency signal near the critical pressure ${P}_{c1}\ensuremath{\sim}$ 0.7 GPa. We argue that this change could be due to a reconstruction of the Fermi surface (FS) in ${\mathrm{CsV}}_{3}{\mathrm{Sb}}_{5}$. To interpret our experimental data, we computed the electronic band structures and FS of ${\mathrm{CsV}}_{3}{\mathrm{Sb}}_{5}$ using ab initio density functional theory. Our results indicate that both the electronic bands and FS of ${\mathrm{CsV}}_{3}{\mathrm{Sb}}_{5}$ are highly sensitive to external pressure. The deformation of FS pockets with increasing pressure qualitatively explains our experimental observations. The pressure-driven FS instability in ${\mathrm{CsV}}_{3}{\mathrm{Sb}}_{5}$ may induce changes in its electronic states, such as superconductivity, charge density wave, nontrivial topology, and more. Therefore, these results are invaluable for gaining insights into these electronic states in ${\mathrm{CsV}}_{3}{\mathrm{Sb}}_{5}$, as well as in other kagome materials.

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