Strain-Induced Antiferromagnetic Phase in CeAuSb$_2$

We present results of the electrical transport measurements under uniaxial pressure on the antiferromagnet CeAuSb$_2$. In the unstrained system, the resistivity along [100] shows a sharp drop at the N$\acute{\rm e}$el temperature ($T$${\rm_N} \approx$ 6.5 K), suggesting a first order transition. With compression along [100] by $\approx$ 0.3 $\%$, the transition splits into two continuous transitions, at temperatures $T_{1}$ and $T_{2}$. $T_{1}$ is fully suppressed at a compression of $\approx$ 0.6 $\%$, and in pressure ramps at low temperature this transition is a sharp cusp with hysteresis, indicating a first-order transition. $T_{2}$, on the other hand, rises continuously with increasing compression, reaching 9 K at 1.2 $\%$ compression. At present, the nature of the strain-induced phase between $T_{1}$ and $T_{2}$ is not clear.