Exponential suppression of bit-flips in a qubit encoded in an oscillator

By R. Lescanne, M. Villiers, T. Peronnin, Alain Sarlette, M. Delbecq, B. Huard, T. Kontos, Mazyar Mirrahimi, Zaki Leghtas. Nature Physics, 2019

315 citations recorded by the source corpus.

A quantum system interacts with its environment—if ever so slightly—no matter how much care is put into isolating it1. Therefore, quantum bits undergo errors, putting dauntingly difficult constraints on the hardware suitable for quantum computation2. New strategies are emerging to circumvent this problem by encoding a quantum bit non-locally across the phase space of a physical system. Because most sources of decoherence result from local fluctuations, the foundational promise is to exponentially suppress errors by increasing a measure of this non-locality3,4. Prominent examples are topological quantum bits, which delocalize information over real space and where spatial extent measures non-locality. Here, we encode a quantum bit in the field quadrature space of a superconducting resonator endowed with a special mechanism that dissipates photons in pairs5,6. This process pins down two computational states to separate locations in phase space. By increasing this separation, we measure an exponential decrease of the bit-flip rate while only linearly increasing the phase-flip rate7. Because bit-flips are autonomously corrected, only phase-flips remain to be corrected via a one-dimensional quantum error correction code. This exponential scaling demonstrates that resonators with nonlinear dissipation are promising building blocks for quantum computation with drastically reduced hardware overhead8. The choice of the physical system that represents a qubit can help reduce errors. Encoding them in the quadrature space of a superconducting resonator leads to exponentially reduced bit-flip rates, while phase-flip errors increase only linearly.

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

View Paper: https://www.semanticscholar.org/paper/a5d33a0564431780f2394cfa291c509e0d3fad8a

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Artificial Intelligence

In Atomic and Molecular Physics, and Optics

Citations in the corpus

Quantum information processing and quantum optics with circuit quantum electrodynamics (2020, background): “Such brute-force approaches are viable up to around 1,000 qubits — a loose estimate — limited primarily by packaging, signal routing and the size of dilution refrig-a”
Exponential suppression of bit or phase errors with cyclic error correction (2021, background): “[52] 2020 Cat States N/A 1 single shot Superconducting”