Cryogenic RF Filter Staging for Low-Power Superconducting Qubits
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing quantum computing devices using superconducting qubits require substantial power to generate radio frequency signals due to the need for high signal intensity, which leads to increased power dissipation and noise, especially when a large number of qubits are involved, and current attenuator-based thermalization methods reduce signal intensity and require excessive power generation.
Innovation Solution
The use of cooled filters instead of attenuators for thermalizing radio frequency signals, which reduces signal energy dissipation and power requirements by allowing lower signal intensity and optimizing noise reduction, enabling efficient thermalization and reducing the need for RF amplifiers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high signal intensity is used to drive qubits, then qubit operation reliability is improved, but power dissipation and noise increase
Solution Approach 1:
The system divides the signal path into multiple temperature stages (room temperature, intermediate temperature, and cryogenic temperature stages), with filters placed at each stage to progressively thermalize the RF signals. This segmentation allows the signal to be attenuated in controlled steps rather than requiring a single high-power attenuation point, reducing overall power dissipation while maintaining qubit operation reliability.
Solution Approach 2:
Coolable filters are introduced as intermediary components between the signal generator and the qubits. These filters actively thermalize the RF signals by converting excess signal energy into heat that can be managed through cooling systems, thereby reducing the power burden on the signal generator and minimizing noise while preserving signal integrity for qubit operation.
2Temperature
If attenuators are used to thermalize signals, then signal thermalization is achieved, but excessive power generation is required
Solution Approach 1:
The patent replaces passive attenuators with active coolable filters that can be thermally managed. Instead of relying solely on resistive attenuation which dissipates power as heat, the system uses filters whose thermal state can be controlled and cooled, allowing signal thermalization to occur through controlled energy dissipation in cooled components rather than requiring continuous high-power generation.
Solution Approach 2:
The system changes the temperature parameter of the filtering components along the signal path. By placing filters at different temperature stages (with intermediate and cryogenic temperature filters), the signal is progressively thermalized to match the qubit operating temperature. This parameter change approach allows efficient power management because each filter operates at its optimal temperature, reducing the total power required compared to using room-temperature attenuators throughout the path.
3Ease of manufacture
If standard CMOS technology is used, then manufacturing ease is improved, but signal power requirements are not met
Solution Approach 1:
The patent extracts the high-power signal generation function from the CMOS control electronics and places it at room temperature, while the CMOS components only handle low-power control and readout signals. The high-power RF signals are generated by dedicated amplifiers or oscillators outside the CMOS system, then thermalized through the coolable filters before reaching the qubits. This extraction allows standard CMOS technology to be used for manufacturing while the power requirements are satisfied by separate high-power components.
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 reduces power dissipation and the required signal level, making it compatible with standard low-power CMOS technology, allowing for the integration of large quantum computing systems and improving the real-time behavior of qubits.
Implementation Method 1
one or more coolable filters, the latter configured for thermalizing RF signals from the signal generators
Implementation Method 2
one or more cooled filters arranged in this intermediate stage
Data Source
AI summary
A quantum computer hardware apparatus may include a first stage, which is connected to one or more signal generators, and a second stage adapted to be cooled down at a lower temperature than the first stage. Superconducting qubits are arranged in the second stage. The signal generators are configured, each, to generate radio frequency (RF) signals to drive the qubits, in operation. The apparatus may further include an intermediate stage between the first stage and the second stage, wherein the intermediate stage comprises one or more coolable filters, the latter configured for thermalizing RF signals from the signal generators. Related methods for thermalizing radio frequency signals in a quantum computer hardware apparatus are also disclosed.