Patent ID: 9691962
Date: 2017-06-27
CPC Classifications: G06N,H01L,H01P,H03F,H03H,H04Q

Claim:
1. A method of configuring a microwave apparatus, the method comprising: providing a cavity-qubit system comprising a qubit and a readout resonator, the cavity-qubit system configured to output a microwave readout signal; configuring a lossless superconducting circulator to receive the microwave readout signal from the cavity-qubit system and transmit the microwave readout signal according to a rotation; connecting a quantum limited directional amplifier to amplify the microwave readout signal, such that amplification takes place in one direction; connecting a directional coupler to the quantum limited directional amplifier, the directional coupler configured to enable biasing of at least one of the quantum limited directional amplifier and the lossless superconducting circulator to set a working point; connecting a microwave bandpass filter configured to transmit in a microwave frequency band, the microwave bandpass filter configured to pass the microwave readout signal while blocking electromagnetic radiation outside of the microwave frequency band, wherein the microwave bandpass filter is operatively connected to the quantum limited directional amplifier to receive input of the microwave readout signal; and configuring a low-loss infrared filter having a distributed Bragg reflector integrated into a transmission line, the low-loss infrared filter being configured to block infrared electromagnetic radiation while passing the microwave readout signal, the low-loss infrared filter being operatively connected to the microwave bandpass filter to receive input of the microwave readout signal.