Squeezing quantum states extends qubit coherence 160-fold

Researchers have achieved a 160-fold improvement in bit-flip time using squeezed cat qubits compared to standard cat qubits, a development that brings fault-tolerant quantum computation closer to reality. The work uses “squeezing,” a technique originally refined for gravitational wave detection, to redistribute uncertainty and dramatically reduce bit-flip errors. This approach potentially allows for quantum processor architectures requiring far fewer physical qubits per logical qubit, a significant reduction from the hundreds to thousands typically needed. The team’s findings demonstrate that carefully choosing how information is encoded can lead to more resilient qubits. This enhancement stems from a technique where uncertainty is redistributed to a noise-sensitive quadrature, effectively shielding the qubit from environmental interference. The team engineered a dissipator, a component that introduces controlled energy loss, designed to stabilize squeezed states, the foundation of these “moon cat” qubits, by coupling the memory mode hosting the qubit to an ancillary buffer mode. This process involves an additional term in the memory-buffer Hamiltonian proportional to a parameter, λ, which quantifies the deviation from coherent states. The researchers operate in a regime where eight times the product of the coupling strength and cat amplitude is significantly less…