Hybrid Wire Gate Layout for Localization Length Measurement

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Solution Overview

Problem

Accurately measuring the localization length (LL) in hybrid superconductor-semiconductor devices is challenging due to isolating semiconductor contributions from superconductor contributions and efficiently measuring multiple individual wire segments under consistent processing conditions, which affects the performance of topological quantum computing devices.

Innovation Solution

A hybrid LL measurement device is employed, utilizing a plurality of contact gates and a conductance sensor to measure conductance values of wire segments with varying lengths, applying magnetic fields to suppress supercurrents, and using exponential curve-fitting to estimate LL based on conductance scaling, thereby isolating semiconductor contributions and optimizing measurement efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional measurement methods are used to measure localization length in hybrid superconductor-semiconductor devices, then measurement can be performed, but the measurement precision is poor due to inability to isolate semiconductor contributions from superconductor contributions

Engineering Contradiction:

Improvelocalization length measurement precisionVSAvoiddifficulty in isolating semiconductor contributions

Core Design Contradiction:

Measurement precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The wire is divided into multiple segments with different lengths by introducing plunger gates between contact gates. Each segment can be independently measured, allowing the localization length to be extracted from the length dependence of conductance. This segmentation enables isolation of semiconductor contributions by measuring how conductance scales with segment length.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The measurement method varies the length parameter of wire segments by adjusting plunger gate positions and measures conductance at different lengths. By changing the length parameter and observing conductance scaling behavior, the localization length can be precisely determined while separating semiconductor from superconductor contributions.

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If multiple individual wire segments are measured separately under consistent processing conditions, then accurate LL measurement can be achieved, but the measurement time and complexity increase

Engineering Contradiction:

ImproveLL measurement accuracyVSAvoidmeasurement time for multiple wire segments

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

Multiple wire segments are merged into a single continuous wire structure with different length sections defined by gate positions. This allows simultaneous measurement of multiple segment lengths through a single conductance measurement setup, reducing measurement time while maintaining the ability to extract localization length from length dependence.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The measurement device is designed with multiple contact gates and plunger gates that can define various wire segment lengths from a single wire. This multi-functional gate structure allows the same device to measure conductance for multiple different effective lengths, eliminating the need for separate measurements on multiple individual wires.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Measurement precision

If supercurrents are present during measurement, then conductance measurement can be performed, but the measurement accuracy deteriorates due to interference with localization length measurement

Engineering Contradiction:

Improveconductance measurement accuracyVSAvoidsupercurrent interference

Core Design Contradiction:

Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

Plunger gates are used to create potential barriers that suppress supercurrent flow before conductance measurement is performed. By applying negative voltages to plunger gates, the device prevents supercurrent from reaching the measurement region, eliminating its harmful interference with the localization length measurement while allowing normal conductance measurement.

Inventive Principle:

Principle #9Preliminary anti-action

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

The solution enables precise LL measurement, facilitating quality control and performance benchmarking of topological quantum computing devices by accurately determining the LL, which influences MZM formation and device size, thus enhancing device performance.

Implementation Method 1

a conductance sensor electrically coupled to the plurality of contact gates

Methodology Applied

Scientific EffectElectrical Conduction: Conduction (electrical)

Implementation Method 2

applying magnetic fields to suppress supercurrents

Methodology Applied

Scientific EffectMagnetic Field: Magnetic Field

Data Source

PatentUS20250362122A1Hybrid wire localization length measurement device

Publication Date: 2025.11.27 MICROSOFT TECHNOLOGY LICENSING LLC

AI summary

A superconductor-semiconductor device is provided, including a hybrid superconductor-semiconductor wire. The superconductor-semiconductor device may further include a hybrid localization length (LL) measurement device including a plurality of contact gates located above the hybrid superconductor-semiconductor wire in a thickness direction. The hybrid LL measurement device may further include a conductance sensor electrically coupled to the plurality of contact gates.