Superconducting Qubits

Transmon, flux, fluxonium, and gatemon qubits

Trapping Technique

1. Qubits are fabricated as superconducting circuits on a chip substrate
2. Josephson junctions and capacitors create the qubit energy levels
3. No physical trapping required; confinement is through circuit design
4. Qubits are fixed in position on the chip surface
5. Cooled to millikelvin temperatures to maintain superconductivity

Gate Mechanism

1. Single-qubit gates performed via microwave pulses applied through control lines
2. Microwave frequency matches qubit transition frequency for resonant driving
3. Pulse duration and phase control rotation angle and axis
4. Two-qubit gates use capacitive or inductive coupling between neighboring qubits
5. Coupling strength controlled by circuit geometry and applied DC voltages
6. CZ or iSWAP gates implemented via controlled phase accumulation or state swapping