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Abstract

We present results of measurements of resistivity of CeAuSb2 under the combination of c-axis magnetic field and in-plane uniaxial stress. In unstressed CeAuSb2 there are two magnetic phases. The low-field A phase is a single-component spin-density wave (SDW), with q = (eta, +/-eta, 1/2), and the high-field B phase consists of microscopically coexisting (eta, eta, 1/2) and (eta, -eta, 1/2) spin-density waves. Pressure along a < 100 > lattice direction is a transverse field to both of these phases and so initially has little effect, however it eventually induces new low-and high-field phases in which the principal axes of the SDW components appear to have rotated to the < 100 > directions. Under this strong < 100 > compression, the field evolution of the resistivity is much smoother than at zero strain: In zero strain, there is a strong first-order transition, while under strong < 100 > it becomes much broader. We hypothesize that this is a consequence of the uniaxial stress lifting the degeneracy between the (100) and (010) directions.