Circuit Quantization and Qubit Modalities
Hamiltonians, zero-point fluctuations, transmon, flux qubit and fluxonium.
Explore the 10 concepts
Concept 09Circuit nodes and flux variablesNode fluxes provide generalized coordinates for lumped superconducting circuits.Concept 10Lagrangian and Hamiltonian formulationClassical circuit energies lead to a Hamiltonian suitable for quantization.Concept 11Canonical quantization of LC circuitsCircuit flux and charge become noncommuting observables.Concept 12Zero-point voltage and currentEven the circuit ground state contains quantum electrical fluctuations.Concept 13Cooper-pair boxCharging energy and Josephson tunneling compete to create an artificial atom.Concept 14Transmon qubitA large Josephson-to-charging energy ratio suppresses charge dispersion while retaining anharmonicity.Concept 15Flux qubitA superconducting loop can encode states with different persistent-current orientations.Concept 16FluxoniumA small junction shunted by a superinductance produces rich flux-dependent spectra.Concept 17Phase qubits and potential wellsMetastable Josephson potential wells can encode a few low-lying quantum levels.Concept 18Anharmonicity and leakageNonuniform energy-level spacing enables selective qubit operations.