Strongly Forbidden Thermodynamic Oscillations in Quasi-One-Dimensional Conductors

We theoretically show that strongly forbidden oscillations of a specific heat have to exist in metallic phases of some quasi-one-dimensional (Q1D) conductors. They appear due to electron-electron interactions under condition of the magnetic breakdown phenomenon between the so-called open interference electron orbits. We argue that such forbidden thermodynamic oscillations can exist in Q1D conductors (TMTSF)${}_2$ClO${}_4$ and (Per)${}_2$Au(mnt)${}_2$, where TMTSF stands for tetramethyltetraselenafulvalene, Per is polycyclic aromatic hydrocarbon and mnt is mononitrotoluene, and suggest to discover them.