Speaker
Description
Developing a quantum computer is the subject of intense academic and industrial research, due to its promise to solve classically intractable problems. As a consequence, quantum computing is developing rapidly, with recent advances suggesting the feasibility of quantum error correction on a large scale [1]. As with any nascent technology though, many questions remain, regarding the engineering feasibility of such a machine or its place in a world of finite resources for example. In both cases, a typical concern are the energy needs of a future quantum computer.
Here we focus on superconducting cat-qubits, which are presumed to use fewer physical qubits for error correction than other platforms thanks to their noise bias, a property named ‘hardware- efficiency’ [2,3]. As of yet, no effort has been made to quantify the energy consumption of such an approach, leaving the question of energy efficiency unanswered.
In this talk, we detail how to approach the energy consumption of a quantum error correction code running on a superconducting cat-qubit based processor. Using the Metric – Noise – Resource methodology developed in [4] we show how individual cat qubit gates can be optimized for their energy consumption at fixed fidelity. The simulation of a noisy repetition code [5] based on these gates allows us to analyze the resource efficiency of a logical qubit. Finally, we identify the overhead cost of current enabling hardware, pointing to a future research direction for the community at large.
[1] R. Acharya et al., Quantum Error Correction below the Surface Code Threshold, arXiv:2408.13687.
[2] É. Gouzien, D. Ruiz, F.-M. Le Régent, J. Guillaud, and N. Sangouard, Performance Analysis of a Repetition Cat Code Architecture: Computing 256-bit Elliptic Curve Logarithm in 9 Hours with 126 133 Cat Qubits, Phys. Rev. Lett. 131, 040602 (2023).
[3] U. Réglade et al., Quantum control of a cat qubit with bit-flip times exceeding ten seconds, Nature 629, 778 (2024).
[4] M. Fellous-Asiani, J. H. Chai, Y. Thonnart, H. K. Ng, R. S. Whitney, and A. Auffèves, Optimizing Resource Efficiencies for Scalable Full-Stack Quantum Computers, PRX Quantum 4, 040319 (2023).
[5] J. Guillaud and M. Mirrahimi, Repetition Cat Qubits for Fault-Tolerant Quantum Computation, Phys. Rev. X 9, 041053 (2019).
