Field Tuned Quantum Criticality In YFe2Al10

Most studies of quantum criticality have been carried out in $f$-electron based heavy fermions, and the observation and description of the quantum critical behaviors in systems where magnetism comes from d-electrons have been very limited. YFe$_{2}$Al$_{10}$ is a rare d-electron compound that displays pronounced non-Fermi liquid behaviors, including divergencies in the magnetic susceptibility ($\chi $ $\sim$ T$^{-\gamma}$, $\gamma =$1.4) and magnetic specific heat (C$_{\mathrm{M}}$/T $\sim$ -log T). We propose a carried out a scaling analysis of $\chi $(B,T) and C(B,T)/T that indicates YFe2Al10 is located very close to a B$=$0 QCP. We propose a singular free energy and a scaling function that consistently explains the critical exponents as well as the QC-Fermi liquid crossover in terms of a scaling variable T/B$^{0.6}$ Unusually, we find that the spatial dimension d is equal to the dynamical exponent z, and considering the two-dimensional anisotropy of the magnetic susceptibility, we infer that d$=$z$=$2. Hyperscaling is established by the internal consistency of our analysis, and the decidedly non-mean field exponents argue that QC fluctuations are protected since YFe2Al10 is likely a system that is below its upper critical dimension. These experimental observations suggest that YFe$_{2}$Al$_{10}$ is a unique 3d-electron based system that is quantum critical without the need for fine tuning.