Radiofrequency-to-baseband conversion for quantum pulse dispersion

Solution Overview

Problem

Current techniques for mitigating dispersion-induced distortions in baseband pulses during radiofrequency-to-baseband conversion in quantum computing are either inefficient, computationally intensive, or impractical, particularly when using non-superconducting cables, as they reduce the number of quantum gate operations or require expensive superconducting cables.

Innovation Solution

Implementing a system that generates radiofrequency pulses at room temperature, transmits them through non-superconducting cables, and converts them to baseband pulses using an envelope detector near superconducting cables, thereby reducing dispersion-induced distortions without the need for long wait times or complex deconvolution computations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If baseband pulses are transmitted through non-superconducting cables, then the system can use room temperature electronics and reduce cost, but the baseband pulses suffer from dispersion-induced distortion

Engineering Contradiction:

ImprovecostVSAvoidpulse shape accuracy

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent applies pre-distortion to baseband pulses before transmission through non-superconducting cables. The pre-distorted pulse is designed to compensate for the known dispersion characteristics of the cable, so that after transmission and conversion, the pulse recovers its intended shape. This preliminary action eliminates the need for expensive superconducting cables while maintaining pulse accuracy.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent transforms the baseband pulse parameters in the frequency domain by applying a pre-distortion filter that modifies the spectral content. This parameter transformation in the frequency domain compensates for the dispersion-induced phase shifts that occur during transmission through non-superconducting cables.

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If deconvolution computations are applied to pre-distort baseband pulses, then pulse shape accuracy can be maintained, but the computational complexity increases significantly

Engineering Contradiction:

Improvepulse shape accuracyVSAvoidcomputational complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex time-domain deconvolution computations with a simpler frequency-domain filtering approach. By transforming the pre-distortion problem into the frequency domain, the system uses straightforward spectral multiplication instead of computationally intensive iterative deconvolution algorithms, significantly reducing computational complexity while maintaining pulse shape accuracy.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Manufacturing precision

If long wait times are inserted between consecutive baseband pulses, then dispersion-induced distortion is reduced, but the number of quantum gate operations decreases

Engineering Contradiction:

Improvepulse shape accuracyVSAvoidquantum gate operations per coherence time

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The patent applies pre-distortion to baseband pulses before transmission through non-superconducting cables. The pre-distorted pulse is designed to compensate for the known dispersion characteristics of the cable, so that after transmission and conversion, the pulse recovers its intended shape. This preliminary action eliminates the need for expensive superconducting cables while maintaining pulse accuracy.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent transforms the baseband pulse parameters in the frequency domain by applying a pre-distortion filter that modifies the spectral content. This parameter transformation in the frequency domain compensates for the dispersion-induced phase shifts that occur during transmission through non-superconducting cables.

Inventive Principle:

Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach allows for efficient and distortion-free transmission of baseband pulses to qubit devices, enhancing the number of quantum gate operations within the coherence time without the expense of superconducting cables, thus improving the operational efficiency of quantum computing systems.

Implementation Method 1

a signal converter that can convert the radiofrequency signal into a baseband signal. In various aspects, such radiofrequency-to-baseband conversion can reduce a dispersion-induced distortion associated with driving the qubit.

Methodology Applied

Scientific EffectRadiofrequency-to-baseband conversion:

Data Source

PatentUS11949439B2Mitigating baseband pulse dispersion via radiofrequency-to-baseband conversion

Publication Date: 2024.04.02 INTERNATIONAL BUSINESS MACHINE CORPORATION

AI summary

Systems and techniques that facilitate mitigation of baseband pulse distortion via radiofrequency-to-baseband conversion are provided. In various embodiments, a system can comprise a qubit. In various aspects, the system can further comprise a signal generator that can produce a radiofrequency signal. In various instances, the system can further comprise a signal converter coupled between the qubit and the signal generator. In various cases, the signal converter can convert the radiofrequency signal into a baseband signal. In various aspects, such radiofrequency-to-baseband conversion can reduce a dispersion-induced distortion associated with driving the qubit.