Quantum fluctuations in the quasi-one-dimensional non-Fermi liquid system <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>CeCo</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi>Ga</mml:mi><mml:mn>8</mml:mn></mml:msub></mml:mrow></mml:math> investigated using <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>μ</mml:mi><mml:mi>SR</mml:mi></mml:mrow></mml:math>
A. Bhattacharyya, D. T. Adroja, J. S. Lord, Le Wang, Yun Shi, K. Panda, Huiqian Luo, A. M. Strydom
Abstract
Reduced dimensionality offers a piece of crucial information in deciding the type of the quantum ground state in heavy fermion materials. Here we have examined the stoichiometric ${\mathrm{CeCo}}_{2}{\mathrm{Ga}}_{8}$ compound, which crystallizes in a quasi-one-dimensional crystal structure with Ga-Ce-Co chains along the $c$ axis. The low-temperature behavior of the magnetic susceptibility ($\ensuremath{\chi}\ensuremath{\sim}{T}^{\ensuremath{-}0.2}$), heat capacity (${C}_{p}/T\ensuremath{\sim}\ensuremath{-}lnT$), and resistivity ($\ensuremath{\rho}\ensuremath{\sim}{T}^{n}$ with $n\ensuremath{\sim}1$) strongly confirms the non-Fermi liquid ground state of ${\mathrm{CeCo}}_{2}{\mathrm{Ga}}_{8}$. We study the low-energy spin dynamics of the ${\mathrm{CeCo}}_{2}{\mathrm{Ga}}_{8}$ compound utilizing zero-field (ZF) and longitudinal-field muon spin relaxation ($\ensuremath{\mu}\mathrm{SR}$) measurements. ZF-$\ensuremath{\mu}\mathrm{SR}$ measurement reveals the absence of long-range magnetic ordering down to 70 mK. Interestingly, below 1 K the electronic relaxation rate rises sharply, suggesting the appearance of low-energy quantum spin fluctuations in ${\mathrm{CeCo}}_{2}{\mathrm{Ga}}_{8}$.