Time crystals for exciton polaritons in a TMDC nanoribbon embedded in an optical microcavity

We investigated the dynamics of a Bose-Einstein condensate of exciton polaritons in a nanoribbon of transition metal dichalcogenides (TMDCs), such as MoSe₂, embedded in a microcavity in the presence of an external periodic potential. We have shown that the system exhibits signs of a time crystalline phase [1]. It has been demonstrated that this phase prevails even as the width of this ribbon is increased to infinity. This was demonstrated by the fact that the calculated polariton spatial density profile is characterized by self-sustained oscillations over time. This polariton density profile was calculated by solving the quantum Lindblad master equation for the density matrix within the mean field approximation. We also go beyond mean field theory and consider the first-order correction due to the addition of quantum noise and show that our results still hold even in this regime. This novel time crystal (TC) proposal has the advantage of being, in principle, achievable even at room-temperature.