Superconducting Resonator Thermometry for Qubit Temperature Sensing

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Determining the temperature of quantum computing devices is challenging due to the effects of temperature measurements on their operation and the ineffectiveness of conventional thermodynamic methods, such as conduction, convection, and radiation, for superconducting quantum devices.

Innovation Solution

A system that determines the temperature of superconducting resonators based on frequency shifts caused by changes in kinetic inductance, using a combination of simulation and measurement to estimate and compare frequencies at reference and operating temperatures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional thermodynamic methods (conduction, convection, radiation) are used to measure temperature, then temperature measurement is possible, but the measurement affects quantum device operation and is ineffective for superconducting quantum devices

Engineering Contradiction:

Improvetemperature measurement capabilityVSAvoidquantum device operation stability

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent introduces a superconducting resonator as an intermediary element that couples to the quantum device. The resonator experiences temperature changes from the quantum device and translates them into measurable frequency shifts, allowing indirect temperature measurement without direct thermal contact that would disturb the quantum device operation.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces conventional thermodynamic measurement methods with a quantum mechanical approach using superconducting resonators. Instead of using physical thermal contact (conduction), fluid flow (convection), or electromagnetic radiation (radiation), the system uses quantum-level frequency measurements of the resonator that are sensitive to temperature changes without requiring direct thermal interaction with the quantum device.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Loss of information

If direct temperature measurement is attempted, then temperature data can be obtained, but the measurement process interferes with quantum device operation

Engineering Contradiction:

Improvetemperature data acquisitionVSAvoidmeasurement interference on quantum operation

Core Design Contradiction:

Loss of informationVSObject-affected harmful factors

Solution Approach 1:

The superconducting resonator serves as a mediator that is thermally coupled to the quantum device but electrically isolated. It captures temperature information through thermal equilibrium while its quantum state remains distinct, allowing temperature data acquisition without direct measurement interference on the quantum device's operational state.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The resonator creates a copy of the temperature information from the quantum device. By measuring the resonator's frequency (which is a copy of the temperature state), the system obtains temperature data without directly measuring the quantum device itself, thus avoiding measurement back-action on the quantum system.

Inventive Principle:

Principle #26Copying

3Measurement precision

If conventional temperature sensors are used, then temperature can be measured, but the sensors are ineffective for superconducting quantum devices

Engineering Contradiction:

Improvetemperature measurement accuracyVSAvoidcompatibility with superconducting quantum devices

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent changes the measurement parameter from direct thermal properties (which conventional sensors measure) to the resonant frequency of a superconducting resonator. This frequency parameter is highly sensitive to temperature changes in the superconducting regime while being compatible with quantum device operation, thus adapting the measurement approach to the specific requirements of superconducting quantum devices.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The system uses composite superconducting structures (resonators made from superconducting materials) that combine the properties needed for both quantum device compatibility and temperature sensitivity. These composite structures enable measurement functionality that neither conventional sensors nor simple superconducting elements could provide alone.

Inventive Principle:

Principle #40Composite materials

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

Enables efficient, effective, and autonomous temperature determination of quantum computing devices, maximizing the longevity of superconductive qubits by accurately measuring temperature changes affecting their operation.

Implementation Method 1

a frequency shift exhibited by the superconducting resonator due to a change in kinetic inductance with a change in temperature

Methodology Applied

Scientific EffectKinetic inductance:

Data Source

PatentUS11879789B2On-chip thermometer for superconducting quantum computing devices

Publication Date: 2024.01.23 INTERNATIONAL BUSINESS MACHINE CORPORATION

AI summary

Techniques regarding determining the temperature of one or more quantum computing devices are provided. For example, one or more embodiments described herein can comprise a system, which can comprise a temperature component that can determine a temperature of a superconducting resonator based on a frequency shift exhibited by the superconducting resonator due to a change in kinetic inductance with a change in temperature.