Non-equilibrium superconductivity and magneto-transport in quantum Kuramoto model

• Applicant: Privatdozent Dr. Alexander Chudnovskiy
• Subject Area: Theoretical Condensed Matter Physics
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 533783251

The main concept of this project is to induce nonequilibrium superconductivity by populating the excited superconducting quantum state with a large number of particles. The existence of the excited quantum state bearing the off-diagonal long-range order (ODLRO) has been discovered recently in course of investigations of the extended Sachdev-Ye-Kitaev (SYK) model. The extension of the SYK model by a local attractive Hubbard interaction exhibited a rich phase diagram that contains the most important phases proper to a high-Tc superconductor, such as the superconducting phase, the pseudogap phase, and the incoherent metal phase. In the insulating pseudogap phase, the extended SYK model maps onto the quantum version of the Kuramoto model. Remarkably, the spectrum of the quantum Kuramoto model contains an excited ODLRO quantum state. The presence of the excited ODLRO-state provides the physical mechanism for creation of the nonequilibrium superconductivity, which remains one of the main avenues towards practical application of superconductors. The ultimate objective of the project is to develop a theory of non-equilibrium phase transition between the insulating (pseudogap) and driven superconducting phases, which adopts the population of the superconducting excited state as the mechanism for superconductivity. This theory will determine the temperature limits at which nonequilibrium superconductivity exists. Furthermore, it will provide with optimal protocols for driven superconductivity in disordered strongly correlated systems. Additionally, by incorporating the external magnetic field in the theoretical framework, the project aims to make predictions on the magneto-transport properties of high-Tc superconductors in the pseudogap phase, both in thermal equilibrium and under non-equilibrium conditions. The work plan of the project foresees completion of two PhD-thesis: one focusing at the nonequilibrium stationary superconductivity in the pseudogap phase, and the other one focusing at the magnetotransport in the pseudogap phase.

• DFG Programme: Research Grants
• International Connection: USA
• Cooperation Partner: Professor Alex Kamenev, Ph.D.