Quantum Decoherence Calculator

Calculate quantum decoherence time, coherence decay, purity, and fidelity degradation for quantum systems.

Coherence Time

Decoherence Rate

Temperature

Coupling Strength

Tab to move between fields

Decoherence Time

0 s

Coherence Decay

0.3679

Purity

0.3679

Fidelity

0.3679

Quality Factor1,000

Thermal Decoherence Time0 s

How to Use This Calculator

Enter Coherence Time (s) — the T₂ time of the qubit; superconducting qubits are typically ~10–100 µs, trapped ions ~seconds.
Enter Decoherence Rate (Hz) — the inverse of the environment's correlation time.
Set Temperature (K): millikelvin temperatures (0.01–0.1 K) are typical for superconducting quantum processors.
Adjust Coupling Strength (0–1) to model weak (0.01) or strong (0.5) system-environment interaction.
Read Decoherence Time (s), Purity (1 = pure state, 0.5 = maximally mixed), and Fidelity to assess qubit quality.

What each input means

ρ(t) = ρ(0) × e^(-t/T₂)

Identify Input Parameters
4 parameters
Coherence Time = 0.000001, Decoherence Rate = 1000000, Temperature = 0.1, Coupling Strength = 0.01 = 4 input(s) provided
Calculate Decoherence Time
Decoherence Time
0.000001 = 0.000001
Calculate Coherence Decay
Coherence Decay
0.3679 = 0.3679
Calculate Purity
Purity
0.3679 = 0.3679
Calculate Quality Factor
Quality Factor
1000 = 1000
Calculate Thermal Decoherence Time
Thermal Decoherence Time
5e-7 = 5e-7

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