Frequency-Noise-Insensitive Universal Control of Kerr-Cat Qubits

Area of Science:

• Quantum computing
• Superconducting circuits
• Quantum information science

Background:

• Kerr-cat qubits show promise for quantum computation.
• Frequency uncertainties pose a challenge to qubit stability and gate fidelity.
• Existing methods struggle to balance robustness with full qubit control.

Purpose of the Study:

• To investigate the impact of frequency uncertainties on Kerr-cat qubit operations.
• To develop novel gate schemes that preserve qubit robustness against frequency noise.
• To enable universal control of Kerr-cat qubits without sacrificing error protection.

Main Methods:

• Theoretical analysis using an effective Kerr oscillator model.
• Numerical simulations to assess gate robustness.
• Development of a universal set of gate schemes for Kerr-cat qubits.

Main Results:

• Kerr-cat qubits demonstrate increased protection against phase errors with higher photon numbers.
• A proposed universal gate scheme maintains robustness to frequency shifts to first order.
• The new schemes allow for robust rotations along nontrivial axes (Y and Z).

Conclusions:

• The developed gate schemes overcome the trade-off between protection and controllability in Kerr-cat qubits.
• This work enables robust universal gate operations on Kerr-cat qubits, crucial for quantum computing.
• Applications include tunable superconducting platforms, mitigating noise from spurious two-level systems.