Effect of strain on charge density wave order in α-U

Abstract

The effect of strain on charge density wave (CDW) order in α-U is investigated within the frame-work of relativistic density-functional theory. The energetical stability of α-U with CDW distortion is enhanced by the tensile strain along a and b axes, which is similar to the case of negative pressure and normal. However, the tensile strain along c axis suppresses the energetical stability of CDW phase. This abnormal effect could be understood from the emergence of a new one-dimensional atomic chain along c axis in α-U. Furthermore, this effect is supported by the calculations of Fermi surface and phonon mode, in which the topological objects and the dynamical instability show opposite behavior between strain along a/b and c axes.