Superconducting Qubit Layout for 3D Cluster States With 2D Wiring

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Solution Overview

Problem

Current methods for scaling up superconducting quantum circuits for error correction, such as surface code and topological one-way quantum computation, face challenges in configuring three-dimensional structures with two-dimensional quantum bit arrays and control wiring, making it difficult to produce large-scale superconducting circuits with error correction functions.

Innovation Solution

A quantum computing system is designed with alternating base configurations of quantum bit groups arranged in columns, where each group is coupled in a specific pattern, and control wiring is configured two-dimensionally to avoid intersections, enabling the generation of two-dimensional or three-dimensional cluster states and surface codes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a two-dimensional quantum computing circuit configuration is implemented, then the physical connection requirements between quantum bits are simplified, but it becomes difficult to satisfy the condition that each quantum bit must be physically connected to at least two other quantum bits

Engineering Contradiction:
Improvephysical connection simplicityVSAvoidquantum bit connectivity
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent transitions from a two-dimensional circuit configuration to a three-dimensional cluster state arrangement. By stacking multiple layers of quantum bits vertically and establishing connections both within layers (horizontal) and between layers (vertical), the system achieves the required connectivity of at least two connections per quantum bit while maintaining the simplicity of two-dimensional wiring within each layer. The third quantum bit coupled to all second quantum bits acts as a vertical connector enabling this multi-layer architecture.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If a three-dimensional quantum computing circuit configuration is implemented, then the connectivity between quantum bits is improved, but the control wiring complexity increases significantly

Engineering Contradiction:
Improvequantum bit connectivityVSAvoidcontrol wiring complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent divides the quantum computing system into multiple base configurations (layers), where each layer contains a manageable subset of quantum bits arranged in a simple columnar structure. This segmentation allows each layer to be controlled independently with simple two-dimensional wiring, while the overall three-dimensional connectivity is achieved through standardized inter-layer connections via the third quantum bits, thereby reducing overall control wiring complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

By organizing quantum bits into a three-dimensional cluster state with multiple stacked layers, the patent achieves enhanced connectivity without proportionally increasing wiring complexity. The vertical stacking allows quantum bits in one layer to connect to quantum bits in adjacent layers through the third quantum bits, creating efficient three-dimensional pathways that reduce the need for long-range two-dimensional connections.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Reliability

If surface code is implemented with traditional wiring, then error correction capability is achieved, but it requires complex three-dimensional wiring that is difficult to realize physically

Engineering Contradiction:
Improveerror correction capabilityVSAvoidwiring structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements surface code error correction by transitioning from traditional planar three-dimensional wiring to a vertical multi-layer architecture. The base configurations are stacked to form a three-dimensional cluster state where error correction operations can be performed within each two-dimensional layer independently, with vertical connections providing the necessary inter-layer entanglement. This approach maintains error correction capability while using simpler two-dimensional control wiring within each layer.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 configuration allows for the realization of two-dimensional or three-dimensional cluster states and surface codes with pseudo two-dimensional superconducting circuits, enhancing the scalability and precision of quantum computing systems.

Implementation Method 1

a first quantum bit group configured from first superconducting quantum bits arranged so as to form a single column without mutual coupling, a second quantum bit group configured from second superconducting quantum bits arranged so as to form a single column with adjacent ones of the second superconducting quantum bits coupled together and each of the second superconducting quantum bits coupled to the first superconducting quantum bit that is arranged in a same row

Methodology Applied
Scientific EffectJosephson effect: Josephson Effect

Data Source

PatentEP4270260A2Quantum computing system and use method for quantum computing system
Publication Date: 2023.11.01 TOKYO UNIVERSITY OF SCIENCE
  • EP4270260A2 patent drawingFigure 1
  • EP4270260A2 patent drawingFigure 2
  • EP4270260A2 patent drawingFigure 3

AI summary

A quantum computing system including plural base configurations each configured including a first quantum bit group configured from first quantum bits arranged so as to form a single column without mutual coupling, a second quantum bit group configured from second quantum bits arranged so as to form a single column with adjacent ones of the second quantum bits coupled together and each of the second quantum bits coupled to the first quantum bit that is arranged in a same row, and a third quantum bit coupled to all of the second quantum bits. The plural base configurations are arranged so as to form a single column with the third quantum bits in adjacent ones of the base configurations coupled together. In a quantum computing circuit configuration, a two-dimensional cluster state or a three-dimensional cluster state is accordingly realized with two-dimensional control wiring, or surface code is accordingly realized with a pseudo two-dimensional superconducting circuit.