Quantum sensing of ultralow temperature in biwire ultracold polar molecules

We present a systematic study of quantum sensing of ultralow temperature in biwire ultracold polar molecules of a quasi-one-dimensional (1D) trap by exploring the dynamics of two physically different qubit models. The two models consist of a trapped impurity atom that act as a temperature quantum sensor interacting with polar molecules reservoir, where dipole moments are aligned head-to-tail across the wires. Our model takes advantage of the adjustable interwire distance to accurately control the precision ultralow temperatures measurement. We show that the system undergoes a transition from Markovian to non-Markovian dynamics, which can be controlled by changing the interwire separation, the dipole-–dipole interaction (DDI), and the temperature. We characterize the thermometric performance using the quantum signal-to-noise ratio for both models and demonstrate that such a quantity exhibits a higher peak at ultralow temperature. We therefore emphasize that ultracold polar molecules are crucial for revolutionizing temperature sensing.