In-plane uniaxial stress study of a low dimensional organic metal

We have studied the effects of in-plane uniaxial stress along both principal axes for the quasi-two-dimensional organic conductor (BEDT-TTF)2KHg(SCN)4 in terms of changes in the magnetotransport properties in high magnetic fields. This class of charge transfer organic metal salts is unique due to the co-existence of both closed and open orbit bands at the Fermi level. We find that stress along both the a- and c-axis directions (in the plane of the quasi-two-dimensional conducting planes) destroys the low temperature density wave state, but in differing ways, and increases the extremal areas of the closed orbit bands. For stress along the a-axis, new low area orbits are induced, and for stress along the c-axis, the quantum oscillations in the Shubnikov de Haas effect take on highly two-dimensional character. We compare our results with predictions made from band structure calculations for in-plane uniaxial stress.