Pressure dependence of two-level systems in disordered atomic chain
  The dependence of two-level systems in disordered atomic chain on pressure, both positive and negative was studied numerically. The disorder was produced through the use of interatomic pair potentials having more than one energy minimum. It was found that there exists a correlation between the energy separation of the minima of two-level systems Delta and the variation of this separation with pressure. The correlation may have either positive or negative sign, implying that the asymmetry of two-level systems may in average increase or decrease with pressure depending on the interplay of different interactions between atoms in disordered state. The values of Delta depend on the sign of pressure. 
A. Shelkan, V. Hizhnyakov
cond-mat.mtrl-sci cond-mat.dis-nn cond-mat.soft