Nonlinear signal distortion corrections through quantum sensing

Abstract

Having accurate gate generation is essential for precise control of a quantum system. The generated gate usually suffers from linear and nonlinear distortion. Previous works have demonstrated how to use a qubit to correct linear frequency distortions but have not commented on how to handle nonlinear distortions. This is an important issue as we show that nonlinear amplitude distortions from the RF electronics can affect Rabi pulses by as much as 10%. We present work that demonstrates how a transmon qubit can be used as a highly sensitive cryogenic detector to characterize these nonlinear amplitude distortions. We show that a correction can drive these errors down to <1% over a 700 MHz range. This correction technique provides a method to minimize the effects of signal distortions and can be easily applied to broadband control pulses to produce higher fidelity arbitrary quantum gates.

Precise certification of a qubit space

“…The tests of dimension are robust against many deficiencies of real quantum gates. Physical operations on qubits are realized by microwave pulses and suffer from distortions due to nonlinearities of waveform generators [27]. Therefore a simple deviation of the probability distribution from the theoretical prediction [28,29] is insufficient to test for an extra qubit space.…”

Precise certification of a qubit space

“…On the other hand, the potential contribution of external states can lead to systematic errors, hard to correct. Operations on qubits, gates, realized by microwave pulses, suffer from distortions due to nonlinearities of waveform generators [7], so a simple deviation of the probability distribution from the theoretical prediction is not yet a proof of extra space [8]. Therefore, to increase the quality of classical and quantum computation and communication, these systems need precise certification, robust against imperfections of physical implementations.…”

Precise certification of a qubit space

“…The tests of dimension are robust against many defi- * Electronic address: Adam.Bednorz@fuw.edu.pl ciencies of real quantum gates. Physical operations on qubits are realized by microwave pulses and suffer from distortions due to nonlinearities of waveform generators [23]. Therefore a simple deviation of the probability distribution from the theoretical prediction [24] is insufficient to test for an extra qubit space.…”