Nanoribbon Quantum Dot Grid With Wrapped Gates for Coherence Control
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Solution Overview
Problem
Current quantum dot devices face challenges in controlling the electrostatic landscape and maintaining coherence times due to material imperfections and defects, limiting their scalability and control over quantum dot interactions.
Innovation Solution
The development of nanoribbon-based quantum dot devices, where semiconductor nanoribbons are arranged in a grid with gates that wrap around individual portions of the nanoribbons, allowing for increased control of the electrostatic landscape and improved scalability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional quantum dot devices are used, then device structure is simpler, but control over electrostatic landscape and coherence times is weaker
Solution Approach 1:
The patent implements gates that wrap around nanoribbons in a nested configuration, with gates positioned at intersections of first and second nanoribbons. This nested gate structure provides enhanced control over quantum dots formed in the nanoribbon intersections, improving coherence times through better electrostatic control while maintaining a relatively compact device footprint.
Solution Approach 2:
The patent introduces a grid structure with first nanoribbons extending in one direction and second nanoribbons extending in a perpendicular direction, creating a two-dimensional array of quantum dots. This dimensional expansion allows for scalable quantum computing architectures while maintaining uniform control characteristics across the device through the regular grid pattern.
2Manufacturing precision
If quantum dot devices with better control are implemented, then coherence times improve, but manufacturing complexity increases
Solution Approach 1:
The patent divides the quantum dot device into modular units formed at the intersections of first and second nanoribbons. Each intersection creates a discrete quantum dot region that can be independently controlled by gates wrapped around the nanoribbons. This segmentation enables precise control over individual quantum dots while allowing parallel fabrication processes for the nanoribbon grid structure.
Solution Approach 2:
The gate structure in the patent serves multiple functions: it provides electrostatic control over quantum dot formation, enables tuning of inter-dot coupling, and allows for scalable expansion of the quantum dot array. The same gate wrapping architecture can be applied uniformly across all nanoribbon intersections, simplifying the fabrication process while maintaining high control precision.
3Productivity
If nanoribbon grid structure is used, then scalability improves, but device complexity increases
Solution Approach 1:
The patent implements a two-dimensional grid of nanoribbons with first nanoribbons extending in one direction and second nanoribbons extending in a perpendicular direction, creating scalable quantum dot arrays. This dimensional approach allows systematic expansion from small to large-scale quantum computing devices while maintaining uniform control characteristics through the regular grid pattern.
Solution Approach 2:
The patent combines multiple nanoribbons in a grid configuration where first and second nanoribbons intersect and are surrounded by shared gate structures. This merging of nanoribbon elements with common gate control reduces the number of independent control lines needed compared to separately controlled quantum dots, thereby improving scalability while managing device complexity.
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 enables strong spatial localization of quantum dots, better control over quantum dot interactions, and improved scalability, addressing the limitations of conventional quantum dot devices.
Implementation Method 1
applying a first voltage to the gate relative to the source and drain electrodes causes a quantum dot to form in the nanoribbon between the source and drain electrodes
Data Source
AI summary
Quantum dot devices and related methods and systems that use semiconductor nanoribbons arranged in a grid where a plurality of first nanoribbons, substantially parallel to one another, intersect a plurality of second nanoribbons, also substantially parallel to one another but at an angle with respect to the first nanoribbons, are disclosed. Different gates at least partially wrap around individual portions of the first and second nanoribbons, and at least some of the gates are provided at intersections of the first and second nanoribbons. Unlike previous approaches to quantum dot formation and manipulation, nanoribbon-based quantum dot devices provide strong spatial localization of the quantum dots, good scalability in the number of quantum dots included in the device, and/or design flexibility in making electrical connections to the quantum dot devices to integrate the quantum dot devices in larger computing devices.