Building logical qubits in a superconducting quantum computing system

By Jay M. Gambetta, Jerry M. Chow, Matthias Steffen. 2015

591 citations recorded by the source corpus.

The technological world is in the midst of a quantum computing and quantum information revolution. Since Richard Feynman’s famous ‘plenty of room at the bottom’ lecture (Feynman, Engineering and Science23, 22 (1960)), hinting at the notion of novel devices employing quantum mechanics, the quantum information community has taken gigantic strides in understanding the potential applications of a quantum computer and laid the foundational requirements for building one. We believe that the next significant step will be to demonstrate a quantum memory, in which a system of interacting qubits stores an encoded logical qubit state longer than the incorporated parts. Here, we describe the important route towards a logical memory with superconducting qubits, employing a rotated version of the surface code. The current status of technology with regards to interconnected superconducting-qubit networks will be described and near-term areas of focus to improve devices will be identified. Overall, the progress in this exciting field has been astounding, but we are at an important turning point, where it will be critical to incorporate engineering solutions with quantum architectural considerations, laying the foundation towards scalable fault-tolerant quantum computers in the near future.

Subfields: Artificial Intelligence, Atomic and Molecular Physics, and Optics

View Paper: https://www.semanticscholar.org/paper/770731d53dc9bfbdb0c263894dab71aee31dc110

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Citations in the corpus

High-threshold and low-overhead fault-tolerant quantum memory (2023, unknown): “15 for a summary.”
The future of quantum computing with superconducting qubits (2022, background): “Just a few years ago, QPU sizes were limited by control electronics cost and availability, I/O space, quality of control software, and a problem referred to as “breaking the plane” 108 , i.e., routing microwave control and readout lines to qubits in the center of dense arrays.”
Universal Gate for Fixed-Frequency Qubits via a Tunable Bus (2016, background): “Superconducting qubits are a promising implementation for fault-tolerant quantum computing [1], however, proposed circuits will be large — a logical qubit in the surface code could require up to 10(4) physical qubits [2].”
Cavity magnonics (2021, background): “It is three orders of magnitude shorter than the lifetimes of state-ofthe-art superconducting qubit (Gambetta et al., 2017), and even six orders of magnitude shorter than coherence times of state-of-the-art paramagnetic impurities (Wolfowicz et al., 2012).”
Widely Tunable On-Chip Microwave Circulator for Superconducting Quantum Circuits (2017, background): “[55] gives a good overview and summary of the technical challenges relevant to this architecture.”
Quantum error correction: an introductory guide (2019, methodology): “To this end, laboratories at places such as Google [49], IBM Research [71,72] and TU Delft [73] are currently building superconducting devices with the long-21 term goal of realising a surface code logical qubit.”
Tunable Superconducting Qubits with Flux-Independent Coherence (2017, methodology): “Lattices of coupled qubits are proposed to enable errorcorrection algorithms such as the “surface code” [4,5].”
Halving the cost of quantum addition (2017, background): “…the architecture of future error corrected quantum computers, because 2D arrays of qubits with nearest-neighbor connections are possible with many qubit technologies [23, 4, 12, 18, 17] and other well understood error correcting codes either have lower thresholds or require stronger connectivity.”
Qubit allocation (2018, unknown): “Technological reasons restrict the number of possible couplings and their organization [14].”