Hot Accelerated Qubits: Decoherence, Thermalization, Secular Growth and Reliable Late-time Predictions

Understand

We compute how an accelerating qubit coupled to a scalar field - i.e.

• an Unruh-DeWitt detector - evolves in flat space, with an emphasis on its late-time behaviour.
• When calculable, the qubit evolves towards a thermal state for a field prepared in the Minkowski vacuum, with the approach to this limit controlled by two different time-scales.
• For a free field we compute both of these as functions of the difference between qubit energy levels, the dimensionless qubit/field coupling constant, the scalar field mass and the qubit's proper acceleration.