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Two-Qubit Operations for Finite-Energy Gottesman-Kitaev-Preskill Encodings
Ivan Rojkov1, Paul Moser Röggla1, Martin Wagener1
1Institute for Quantum Electronics, <a href="https://ror.org/05a28rw58">ETH Zürich</a>, Otto-Stern-Weg 1, 8093 Zürich, Switzerland and Quantum Center, <a href="https://ror.org/05a28rw58">ETH Zürich</a>, 8093 Zürich, Switzerland.
Physical Review Letters
|September 20, 2024
Summary
We developed methods for finite-energy two-qubit gates on Gottesman-Kitaev-Preskill (GKP) codes. Error correction mitigates issues from ideal gate operations, and new energy-conserving gates reduce the need for correction.
Area of Science:
- Quantum information science
- Quantum error correction
- Quantum computing hardware
Background:
- Gottesman-Kitaev-Preskill (GKP) codes are crucial for fault-tolerant quantum computing.
- Implementing quantum gates with finite energy presents unique challenges for realistic quantum systems.
Purpose of the Study:
- To present techniques for performing two-qubit gates on finite-energy GKP codes.
- To address the challenges of undesired entanglement in physically realistic quantum states.
- To propose novel energy-conserving gate implementations.
Main Methods:
- Application of ideal infinite-energy gate operations to finite-energy GKP states.
- Utilizing recently developed local error-correction protocols.
- Developing and evaluating energy-conserving finite-energy gate implementations.
Main Results:
- Operations designed for ideal codes induce undesired entanglement in finite-energy GKP states.
- Local error-correction protocols effectively mitigate this entanglement.
- Proposed energy-conserving gates largely circumvent the need for additional error correction.
Conclusions:
- Finite-energy effects must be considered for accurate two-qubit gates on GKP codes.
- Local error correction is a viable strategy to improve gate fidelity.
- Energy-conserving gate designs offer a promising path towards more robust quantum operations.
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