Quantum fluctuations in the quasi-one-dimensional non-Fermi liquid system CeCo 2 Ga 8 investigated using μ SR

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 ${\mathrm{CeCo}}_{2}{\mathrm{Ga}}_{8}$.