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arXiv · 1107.1433

Inelastic light scattering measurements of a pressure-induced quantum liquid in KCuF$_3$

S. Yuan·M. Kim·J. Seeley·S. Lal·P. Abbamonte·S. L. Cooper
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Abstract

Pressure-dependent, low temperature inelastic light (Raman) scattering measurements of KCuF$_3$ show that applied pressure above $P^{*} \sim$ 7 kbar suppresses a previously observed structural phase transition temperature to zero temperature in KCuF$_3$, resulting in the development of a $ω\sim$ 0 fluctuational (quasielastic) response near $T \sim$ 0 K. This pressure-induced fluctuational response --- which we associate with slow fluctuations of the CuF$_6$ octahedral orientation --- is temperature independent and exhibits a characteristic fluctuation rate that is much larger than the temperature, consistent with quantum fluctuations of the CuF$_6$ octahedra. A model of pseudospin-phonon coupling provides a qualitative description of both the temperature- and pressure-dependent evolution of the Raman spectra of KCuF$_3$.

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S. Yuan, M. Kim, J. Seeley, S. Lal, P. Abbamonte, S. L. Cooper. 2012-12-07. Inelastic light scattering measurements of a pressure-induced quantum liquid in KCuF$_3$. https://doi.org/10.1103/physrevlett.109.217402

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