Quantum parameter amplifier

Abstract

The invention discloses a quantum parameter amplifier, the quantum parameter amplifier comprises a capacitor module for forming an oscillation amplification circuit, a reflection type microwave resonant cavity and an inductance-adjustable superconducting quantum interference device which are connected in sequence; one end, far away from the reflection type microwave resonant cavity, of the superconducting quantum interference device is grounded; the resonant frequency of the reflection type microwave resonant cavity is equal to the frequency of a signal to be amplified by adjusting the inductance of the inductance-adjustable superconducting quantum interference device; a signal to be amplified is coupled into the oscillation amplification circuit from the capacitor module; the oscillationamplification circuit is used for amplifying the signal to be amplified under the action of the pumping signal, and a plurality of idle frequency signals are generated; a second microwave resonant cavity is included and is connected to the end, away from the capacitor module, of the reflection type microwave resonant cavity, the resonant frequency of the second microwave resonant cavity is equal to the frequency of one idle frequency signal, and the frequency of the pumping signal, in the optimal working mode, of the quantum parameter amplifier does not need to be selected as the frequency multiplication of the to-be-amplified signal.

Description

technical field [0001] The invention belongs to the field of signal amplifiers, in particular to a quantum parameter amplifier. Background technique [0002] In the field of quantum computing, in order to obtain the calculation results of the quantum chip, we need to collect and analyze the output signal of the quantum chip, that is, the qubit read signal. Usually the qubit read signal is very weak, and generally it is necessary to read the signal in the qubit A multi-stage amplifier is added to the output line of the circuit to improve the signal strength. Usually, the pre-stage amplifier adopts a quantum parametric amplifier. Quantum parametric amplifiers operate with low incident noise levels approaching the quantum limit, which is where their name comes from. [0003] The existing quantum parametric amplifier works based on the principle of nonlinear frequency mixing. In order to effectively amplify the qubit read signal and make the quantum parametric amplifier work in...

AI Technical Summary

Problems solved by technology

[0004] To sum up, in the best working mode of the existing quantum parametric amplifier, that is, the frequency of the pump signal must be selected as the multiplier of the frequency of the signal to be amplified, and there are irrelevant signals whose frequency is very close to the frequency of the signal to be amplified in the output signal. These irrelevant signals are difficult to eliminate through the filter because the frequency is too close to the signal to be amplified. They will interfere with the demodulation process of the qubit read signal, resulting in a significant reduction in the demodulation fidelity and demodulation efficiency of the quantum chip operation results.

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