Method for Reading Out the States of Multiple Qubits, in Particular Superconducting Qubits, Readout Device and Quantum Computer

Simple SummaryContent extracted from patent full text and abstract with AI.

This patent describes a method and system for reading out the states of multiple qubits (especially superconducting or spin qubits) in a quantum computer. Instead of using a complex multi-frequency approach (frequency-division multiplexing) to individually read each qubit, the invention uses a shared probe signal and introduces time delays to the response signals from each qubit. By differentiating the delayed responses in the time domain (time-division multiplexing), each qubit's state can be uniquely identified using a narrower bandwidth signal, thus improving signal integrity and simplifying hardware requirements.

Use CasesContent extracted from patent full text and abstract with AI.

• Reading out large arrays of qubits in superconducting or spin-based quantum computers.
• Improving scale and performance of quantum processors by simplifying readout circuits.
• Reducing hardware complexity and cost in building quantum computers.
• Accelerating quantum research by enabling faster and more reliable qubit state detection.
• Integration into next-generation scalable quantum computing architectures.

BenefitsContent extracted from patent full text and abstract with AI.

• Reduces the complexity of readout electronics as the number of qubits increases, since it doesn't require proportional growth in hardware.
• Improves the signal-to-noise ratio by using a narrower frequency band, leading to more reliable and accurate measurements.
• Minimizes measurement time due to higher-quality, low-noise responses and efficient time-domain processing.
• Allows easier implementation with standard digital processing hardware, like FPGAs, thanks to processing in the time domain instead of frequency domain.
• Lowers hardware costs by removing the need for multiple frequency sources and broadband amplifiers.
• Facilitates the scalability of quantum computers to higher qubit counts without a corresponding increase in system bandwidth or complexity.

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Patent Abstract

The present invention relates to a method for reading out the states of several qubits (Q1-Qn), in particular superconducting qubits and/or spin qubits, wherein for reading out the states, the same sample signal (7) is supplied to the qubits (Q1-Qn) via a common sample line (8), and wherein a separate answer circuit (5), preferably having an answer resonator (4), is assigned to each qubit (Q1-Qn), and wherein in response to the supplied sample signal (7) an answer signal (20) containing information about the state of the respective qubit (Q1-Qn) is output via the respective answer circuit (5), wherein the answer signal (20) of at least one qubit (Q1-Qn) is delayed with respect to the answer signal (20) of at least one further qubit (Q1-Qn). The invention also relates to a read-out device and to a quantum computer.