What Is the Quantum Decoherence & Dephasing Rates Calculator?
Quantum decoherence describes the loss of quantum coherence caused by unwanted environmental coupling.
How Does the Quantum Decoherence & Dephasing Rates Calculator Work?
Computes the transition rates between energy states and the decay of off-diagonal density matrix elements.
Quantum Decoherence & Dephasing Rates Calculator Formula & Variables
The core mathematical equation utilized by this calculator is expressed as:
rac{1}{T_2} = rac{1}{2 T_1} + rac{1}{T_phi}, quad Gamma_2 = rac{Gamma_1}{2} + Gamma_phi
Transverse relaxation decomposes into energy relaxation and pure phase noise.
How to Use the Quantum Decoherence & Dephasing Rates Calculator
- Input experimentally measured T1 (inversion recovery) and T2 (Ramsey or Hahn echo) times in microseconds.
Step-by-Step Example Calculation
Superconducting Transmon Qubit
Input Values:
t1Microseconds:50
t2Microseconds:70
Worked Steps: Computes pure dephasing time T_phi = 233.3 µs with Gamma_1 = 0.02 MHz and Gamma_2 = 0.014 MHz.
Understanding Your Result
T_phi reflects low-frequency flux/charge noise; if T2 approaches 2*T1, the qubit is energy-relaxation limited.
Factors That Affect the Result
- Cryogenic temperature fluctuations, magnetic flux noise, and dielectric loss in substrate materials.
When Should You Use This Calculator?
- Evaluating qubit platform fidelity and benchmarking quantum processors (superconducting, ion trap, spin qubits).
Assumptions & Limitations
- Assumes Markovian exponential decay; non-Markovian 1/f noise may lead to stretched exponential decay.
Frequently Asked Questions
Calculation Accuracy & Reference Note
Conforms to standard Bloch-Redfield relaxation dynamics.