Readout methods and devices for Josephson-junction-based solid-state qubits

摘要

We discuss the current situation concerning measurement and readout ofJosephson-junction based qubits. In particular we focus attention of dispersivelow-dissipation techniques involving reflection of radiation from an oscillatorcircuit coupled to a qubit, allowing single-shot determination of the state ofthe qubit. In particular we develop a formalism describing a charge qubit readout by measuring its effective (quantum) capacitance. To exemplify, we alsogive explicit formulas for the readout time.