Systems and methods for superconducting quantum refrigeration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
There is a need for a reliable heat transfer device capable of achieving temperatures nearing absolute zero, which is essential for modern devices like ultrafast quantum computers and sensors, but existing techniques are inadequate in efficiently cooling to such low temperatures.
Innovation Solution
A solid-state heat transfer technique using repeated adiabatic magnetization/demagnetization cycles of a superconductor as the working substance, with a metallic substrate connected to a first tunnel junction and a heat sink connected to a second tunnel junction, allowing for asymmetric heat transport due to energy gaps, enabling selective cooling of the metal substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If dilution refrigerators are used to achieve low temperatures, then cooling capability is provided, but reliability and efficiency for reaching temperatures nearing absolute zero remain insufficient
Solution Approach 1:
The invention utilizes the superconducting phase transition of the working substance, which occurs when the material transitions from a normal state to a superconducting state upon application of a magnetic field. This phase transition enables adiabatic cooling, allowing the system to reliably achieve temperatures nearing absolute zero by exploiting the thermodynamic properties of the superconducting transition.
Solution Approach 2:
The refrigeration system operates through cyclic magnetization and demagnetization of the working substance. By periodically applying and removing magnetic fields, the system creates repeated adiabatic cooling cycles that progressively lower the temperature of the metallic substrate, enabling reliable achievement of ultra-low temperatures through cumulative cooling effects.
2Temperature
If conventional cooling techniques are used, then some cooling capability is achieved, but efficiency for cooling to temperatures nearing absolute zero is insufficient
Solution Approach 1:
The invention exploits the superconducting phase transition to achieve highly efficient adiabatic cooling. When the working substance transitions from normal to superconducting state under applied magnetic field, the entropy change enables efficient heat removal from the metallic substrate, achieving cooling efficiencies far superior to conventional techniques at temperatures approaching absolute zero.
Solution Approach 2:
The system changes the magnetic field parameter to control the phase state of the working substance. By varying the magnetic field strength between zero and critical values, the system controls the superconducting transition, thereby controlling the cooling process and achieving high cooling efficiency through precise parameter modulation.
3Temperature
If adiabatic magnetization/demagnetization cycles are used, then temperatures nearing absolute zero are achieved, but device complexity increases
Solution Approach 1:
The invention introduces a superconducting working substance as an intermediary between the magnetic field source and the metallic substrate to be cooled. This intermediary undergoes phase transitions that mediate the cooling process, enabling temperature control near absolute zero while simplifying the overall device architecture by using the material's inherent thermodynamic properties rather than complex mechanical cooling mechanisms.
Solution Approach 2:
The invention replaces complex mechanical refrigeration systems with a field-based approach using magnetic field-induced superconducting transitions. This substitution eliminates the need for moving parts, complex thermal management mechanisms, and elaborate cooling infrastructure, thereby reducing device complexity while achieving superior cooling performance.
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 technique effectively cools a 0.3 cm^3 block of Copper by almost two orders of magnitude from 200 mK to 1 mK, demonstrating a significant cooling power of 25 nW and 0.06 nW respectively for 1 cm×1 cm interfaces, scaling with the area, and is suitable for applications in ultrafast quantum computers and sensors.
Implementation Method 1
repeated adiabatic magnetization/demagnetization cycles of a superconductor which acts as the working substance
Implementation Method 2
a first superconducting material having a superconducting state and a normal state when magnetized
Implementation Method 3
repeated adiabatic magnetization/demagnetization cycles of a superconductor
Implementation Method 4
Heat transport between N/N versus N/S junctions is asymmetric because of the appearance of the energy gap
Implementation Method 5
a heat sink connected to the working region at a second tunnel junction, wherein the heat sink is made from a second superconducting material having a second energy gap larger than the first energy gap
Data Source
AI summary
A heat transfer device and method are disclosed. The device includes a working region (i.e., working substance) made from a first superconducting material having a superconducting state and a normal state when magnetized. The first superconducting material has a first energy gap while in the superconducting state. A substrate (i.e., cold reservoir) is connected to the working region at a first tunnel junction. The substrate may be a metallic substrate. A heat sink (i.e., hot reservoir) is connected to the working region at a second tunnel junction. The heat sink is made from a second superconducting material having a second energy gap that is larger than the first energy gap. In a particular example, the heat transfer device includes a metallic substrate is made from Copper, a working region made from Tantalum, a heat sink made from Niobium, and the first and second tunnel junctions are made from Tantalum Oxide.