IFQs Promise Highly Effective Coherence Times With New Gates

Researchers have demonstrated that a standard superconducting circuit, the integer fluxonium qubit, can function as an erasure qubit by utilizing its second excited state for encoding, potentially simplifying the hardware needed for error correction and fault-tolerant quantum computing. The |g⟩ − |f⟩ transition is identical to that of a usual fluxonium qubit and hence is expected to have excellent coherence time, while the |f⟩ − |g⟩ transition is additionally protected from energy relaxation by parity symmetry. Jiakai Wang, Raymond A. Mencia, Vladimir E. Manucharyan, and Maxim G. can treat energy relaxation errors, specifically, transitions from |e⟩ to |g⟩ and |f⟩ to |e⟩, as erasure events, improving the efficiency of quantum error-correcting codes. With optimized circuit parameters and gate…