In condensed matter physics, novel quantum states of matter may emerge due to the strong correlation between electrons, including unconventional superconductivity, complex magnetic order, and quantum criticality. In order to create a predictive understanding of these new phases unexpected by conventional theories, proper materials and control parameters are necessary. My research interest is discovering and investigating new quantum states in a broad range of quantum materials using various experimental techniques, including thermal expansion, thermopower, heat capacity, electrical resistivity, and Hall effect under extreme conditions of low temperature, high pressure, and high magnetic field. I will discuss the relationship between the nematic phase and spin textures in CeAuSb2, a heavy-fermion incommensurate antiferromagnet, via thermal expansion and resistivity measurements. These results suggest a new picture for the complex magnetic order of quantum matter.