Co-Planar Waveguide Flux Qubits With Longer Decoherence Time
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Quantum computing qubits, particularly flux qubits, face short decoherence times due to sources such as material noise from Josephson junction dielectrics and limited connectivity, which restricts the number of qubits that can be coupled and affects computational power.
Innovation Solution
The co-planar waveguide flux qubit design eliminates additional material layers and dielectric sources of decoherence by using a single layer of superconducting material and replaces the third Josephson junction with a co-planar waveguide, allowing for longer decoherence times and increased coupling capabilities through inductive coupling over macroscopic lengths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional flux qubit design with multiple Josephson junctions is used, then qubit functionality is achieved, but decoherence time is short due to material noise from Josephson junction dielectrics
Solution Approach 1:
The patent removes the third Josephson junction and its associated dielectric layers from the traditional flux qubit structure. This extraction eliminates the primary source of material noise and decoherence, directly improving reliability while simplifying the device structure by reducing the number of components and material layers.
Solution Approach 2:
The invention changes the fundamental structure parameter from a multi-junction design to a single-junction design with a continuous superconducting wire. This parameter change transforms the qubit's operational characteristics, enabling longer decoherence times by eliminating dielectric interfaces while maintaining the necessary quantum functionality through modified inductance and capacitance distributions.
2Adaptability or versatility
If traditional flux qubit design is used, then basic qubit operation is achieved, but connectivity is limited restricting the number of coupled qubits
Solution Approach 1:
The patent extends the qubit structure along the spatial dimension by using a long continuous superconducting wire that can physically reach and couple with multiple other qubits. This dimensional extension enables increased connectivity without compromising decoherence time, as the extended structure is made of clean superconducting material without dielectric loss sources.
3Reliability
If additional material layers are used in flux qubit design, then Josephson junction functionality is achieved, but decoherence increases due to dielectric sources
Solution Approach 1:
The patent extracts and removes the dielectric material layers that are necessary for traditional Josephson junction fabrication. By eliminating these lossy dielectric layers, the invention achieves longer decoherence times while actually simplifying the fabrication process, as fewer material deposition and patterning steps are required.
4Adaptability or versatility
If third Josephson junction is included, then flux qubit operation is achieved, but inductive coupling capability is reduced
Solution Approach 1:
The patent removes the third Josephson junction from the flux qubit structure. This extraction eliminates the blocking effect that the junction would have on magnetic flux and inductive coupling, thereby enhancing the qubit's ability to couple with external circuits and other qubits while reducing structural 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 design achieves longer decoherence times and enables coupling with a greater number of qubits, potentially avoiding the embedding problem and improving quantum computing efficiency by distributing inductance and capacitance over a larger area.
Implementation Method 1
the thin film, the quantum device, and the ground plane include a material that is superconducting at a designed operating temperature
Implementation Method 2
allowing for longer decoherence times and increased coupling capabilities through inductive coupling over macroscopic lengths
Data Source
AI summary
A qubit device includes an elongated thin film uninterrupted by Josephson junctions, a quantum device in electrical contact with a proximal end of the elongated thin film, and a ground plane that is co-planar with the elongated thin film and is in electrical contact with a distal end of the elongated thin film, in which the thin film, the quantum device, and the ground plane comprise a material that is superconducting at a designed operating temperature.