Cryogenic Microwave Attenuator Substrates for Better Thermalization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing dissipative devices for quantum applications, such as those used in superconducting qubits, face inefficiencies in both microwave and thermalization aspects, leading to poor coherence times and increased thermal noise due to suboptimal thermal conductivity and Joule heating in cryogenic environments.
Innovation Solution
The development of a microwave attenuator device utilizing a high-thermal conductivity substrate, such as sapphire or Gallium Arsenide, with integrated heat sinks and thin film lines to enhance thermalization and reduce Joule heating, thereby improving the performance of quantum processors by minimizing thermal noise and maintaining clean microwave signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional substrates are used in microwave attenuators, then manufacturing is easier, but thermalization performance deteriorates due to low thermal conductivity
Solution Approach 1:
The patent changes the thermal conductivity parameter of the substrate by selecting materials with high thermal conductivity (sapphire, silicon, gallium arsenide, copper) to improve thermalization performance. This parameter change directly addresses the thermalization issue while maintaining manufacturability through standard fabrication processes.
Solution Approach 2:
The patent employs composite material structures combining high-thermal conductivity substrates with metal heat sinks and conductive adhesives. This composite approach optimizes thermalization by leveraging the complementary thermal properties of different materials while maintaining ease of manufacture through established composite fabrication techniques.
2Reliability
If resistive elements are added to attenuate microwave signals, then signal attenuation is achieved, but Joule heating increases reducing coherence times
Solution Approach 1:
The patent converts the harmful effect of Joule heating into a beneficial thermal management opportunity by implementing high-thermal conductivity substrates and heat sinks. The resistive elements that cause Joule heating are strategically placed on substrates that efficiently conduct heat away, transforming the heat generation issue into an controlled thermal management scenario that maintains low operating temperatures and extends coherence times.
Solution Approach 2:
The patent introduces high-thermal conductivity substrates and heat sinks as intermediary thermal management components between the resistive elements and the cryogenic environment. These intermediaries efficiently transfer heat away from the resistive elements, preventing excessive temperature rise while maintaining the necessary signal attenuation function.
3Reliability
If thermalization is enhanced to reduce thermal noise, then coherence time improves, but device complexity increases
Solution Approach 1:
The patent implements multi-functional substrates that simultaneously serve as mechanical support, electrical insulation, and thermal conduction pathways. By selecting substrates like sapphire, silicon, or gallium arsenide, the same component performs multiple functions, reducing overall device complexity while achieving enhanced thermalization and improved coherence times.
Solution Approach 2:
The patent merges the substrate function with thermal management functionality by integrating heat sinks and conductive pathways directly into the substrate structure. This consolidation eliminates separate thermal management components, reducing device complexity while maintaining effective thermalization for extended coherence times.
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 achieves improved thermalization and microwave performance, extending coherence times and enhancing the overall functionality of quantum processors by effectively mitigating thermal noise and Joule heating in cryogenic environments.
Implementation Method 1
Microwave attenuator devices... utilizing a high-thermal conductivity substrate, such as sapphire or Gallium Arsenide, with integrated heat sinks to enhance thermalization and reduce Joule heating
Implementation Method 2
reduce Joule heating, thereby improving the performance of quantum processors by minimizing thermal noise
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Techniques related to microwave attenuator son high-thermal conductivity substrates for quantum applications are provided. A device can comprise a substrate that provides a thermal conductivity level that is more than a defined thermal conductivity level. The device can also comprise one or more thin film lines, on a top surface of the substrate, comprising an evaporated alloy. Further, the device can comprise one or more vias within the substrate. Respective first ends of the one or more vias are can be connected to respective thin film connectors. Further, respective second ends of the one or more vias can be connected to an electrical ground.