# qiskit.providers.aer.noise.thermal_relaxation_error¶

thermal_relaxation_error(t1, t2, time, excited_state_population=0)[source]

Return a single-qubit thermal relaxation quantum error channel.

Parameters
• t1 (double) – the $$T_1$$ relaxation time constant.

• t2 (double) – the $$T_2$$ relaxation time constant.

• time (double) – the gate time for relaxation error.

• excited_state_population (double) – the population of $$|1\rangle$$ state at equilibrium (default: 0).

Returns

a quantum error object for a noise model.

Return type

QuantumError

Raises

NoiseError – If noise parameters are invalid.

• For parameters to be valid $$T_1$$ and $$T_2$$ must satisfy $$T_2 \le 2 T_1$$.
• If $$T_2 \le T_1$$ the error can be expressed as a mixed reset and unitary error channel.
• If $$T_1 < T_2 \le 2 T_1$$ the error must be expressed as a general non-unitary Kraus error channel.