Qubit Lindblad Relaxation and Dephasing
Separate energy relaxation from lost coherence and watch a qubit’s density matrix remain physical.
Free theory articleSeparate energy relaxation from lost coherence and watch a qubit’s density matrix remain physical.
Concept & interpretation
The Markovian Lindblad master equation describes the evolution of a quantum system interacting with its environment. For a qubit with energy splitting ω, we can model distinct physical processes: energy relaxation (amplitude damping) and pure dephasing.
experiment
You can interact with the quantum trajectory of the qubit in theInteractive Qubit Lindblad Relaxation and Dephasing module.
- Set Initial state to PlusI to start with a coherent superposition.
- Increase the Pure dephasing rate to 0.25 to see the off-diagonal elements shrink faster than the populations change.
- Notice how the Purity drops below 1 as the environment extracts information from the qubit.
- Observe the Minimum Eigenvalue; it remains non-negative at all times, ensuring the state remains a valid, physical density matrix.