Efficient Qubit Error Detection for Data-Qubits Using Parity Qubits: A Novel Approach

TO-111 • PT 1.2849 • As of 10/2023
Peter Grünberg Institute
Theoretical Nanoelectronics (PGI-2)

Technology

Our technology aims to detect decoherence of states in data qubits in a quantum computer. It proposes a method using a parity qubit to identify a decohered state. The parity qubit can be moved using a motion device designed for error correction. Initially, the distance between the data and parity qubits prevents entanglement. By reducing the distance through controlled movements, entanglement is achieved. Data qubits are moved slowly, or over short distances compared to parity qubits to avoid errors. This approach enables reliable detection of incoherent states in data qubits.

Problem addressed

The previous state of the art in quantum computing and quantum cryptography involves the use of qubits, which can exist in multiple states before measurement. Various physical systems, such as electron spins or superconducting circuits, are used to realise qubits. However, these qubits are inherently unstable due to factors like manufacturing limitations and interactions with external sources. To address this, encoding logical quantum states using multiple physical qubits can create more stable systems. Parity qubits are also used for error detection and correction. Several research papers have explored different approaches to qubit implementation and error detection, including the use of electron spins, transport mechanisms, and surface codes.

Solution

Our new solution involves moving parity qubits quickly towards the data qubits for entanglement. Subsequently, the data qubits are moved slowly towards the parity qubits to reduce the distance and achieve entanglement.

If a parity qubit is already entangled with one or more data qubits and needs to be entangled with additional data qubits, it is moved slowly to avoid increased error rates. To further reduce errors, multiple parity qubits can be moved sequentially, each time entangling with a new set of data qubits. By measuring the state of the moved parity qubits, errors can be detected reliably.

Benefits and Potential Use

The device can be used for continuous entanglement and error control between data qubits and parity qubits. It can be applied in various fields where quantum computing is utilized, such as quantum information processing, quantum communication, and quantum cryptography. The device can be implemented using semiconductors like Si/Si-Ge, Ge/Si-Ge or ZnSe heterostructures. The states of parity qubits can be measured using techniques like Pauli spin blockade. The device can also incorporate electromagnetic waves or magnetic gradient fields to adjust the states of data qubits. Overall, this technology offers reliable error detection and control in quantum systems, enhancing the stability and performance of quantum computing applications.

Development Status and Next Steps

Forschungszentrum Jülich has extensive expertise in this field and holds several patents. The technology described above has already been initially verified through prototypes and is continuously being developed further. The Peter Grünberg Institute (PGI-2) – Theoretical Nanoelectronics – already cooperates with numerous national and international companies and scientific partners. Forschungszentrum Jülich focuses on energy and cost-efficient devices, suitable for various emerging technologies. We are continuously seeking for cooperation partners and/or licensees in this and adjacent areas of research and applications.

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