Uniaxial stress effect on quasi-one-dimensional Kondo lattice CeCo₂Ga₈

Quantum critical phenomena in the quasi-one-dimensional limit remain an open issue. We report the uniaxial stress effect on the quasi-one-dimensional Kondo lattice CeCo_2Ga_8 by electric transport and AC heat capacity measurements. CeCo_2Ga_8 is speculated to sit in close vicinity but on the quantum-disordered side of a quantum critical point. Upon compressing the c axis, parallel to the Ce-Ce chain, the onset of coherent Kondo effect is enhanced. In contrast, the electronic specific heat diverges more rapidly at low temperature when the intra-chain distance is elongated by compressions along a or b axis. These results suggest that a tensile intra-chain strain (\varepsilon_c >0) pushes CeCo_2Ga_8 closer to the quantum critical point, while a compressive intra-chain strain (\varepsilon_c<0) likely causes departure. Our work provides a rare paradigm of manipulation near a quantum critical point in a quasi-1D Kondo lattice by uniaxial stress, and paves the way for further investigations on the unique feature of quantum criticality in the quasi-1D limit.