Hi, I have learnt that $T_1$ is the relaxation time for excitation and $T_2$ is the decoherence time, how about dephasing? Say I register multiple qubits (not ideal and have variations between them, but $T_1$ and $T_2$ are both infinity for all of them) with the same info and try to retrieve information from them later. Obviously after some time the information stored within them would be different because they oscillate at slightly different frequencies. Is there a $T_?$ to characterize that (dephasing)?