Combating fluctuations in relaxation times of fixed-frequency transmon qubits with microwave-dressed states

Abstract

With the long coherence time, the fixed-frequency transmon qubit is a promising qubit modality for quantum computing. Currently, diverse qubit architectures that utilize fixed-frequency transmon qubits have been demonstrated with high-fidelity gate performance. Nevertheless, the relaxation times of transmon qubits can have large temporal fluctuations, causing instabilities in gate performance. The fluctuations are often believed to be caused by nearly on-resonance couplings with sparse two-level-system (TLS) defects. To mitigate their impact on qubit coherence and gate performance, one direct approach is to tune the qubits away from these TLSs. In this work, to combat the potential TLS-induced performance fluctuations in a tunable-bus architecture unitizing fixed-frequency transmon qubits, we explore the possibility of using an off-resonance microwave drive to effectively tuning the qubit frequency through the ac-Stark shift while implementing universal gate operations on the microwave-dressed qubit. We show that the qubit frequency can be tuned up to 20 MHz through the ac-stark shift while keeping minimal impacts on the qubit control. Besides passive approaches that aim to remove these TLSs through more careful treatments of device fabrications, this work may offer an active approach towards mitigating the TLS-induced performance fluctuations in fixed-frequency transmon qubit devices.

12 pages,9 figures

References in corpus (14)

• Charge insensitive qubit design derived from the Cooper pair box
• Simple pulses for elimination of leakage in weakly nonlinear qubits
• Complete universal quantum gate set approaching fault-tolerant thresholds with superconducting qubits
• Fidelity of quantum operations
• Decoherence benchmarking of superconducting qubits
• Single-shot qubit readout in circuit Quantum Electrodynamics
• Single-shot qubit readout in circuit Quantum Electrodynamics
• Coherence times of dressed states of a superconducting qubit under extreme driving
• Suppressing relaxation in superconducting qubits by quasiparticle pumping
• Non-Poissonian Quantum Jumps of a Fluxonium Qubit due to Quasiparticle Excitations
• Generalized Tunneling Model for TLS in amorphous materials and its predictions for their dephasing and the noise in superconducting microresonators
• Scalable superconducting qubit circuits using dressed states
• Decoherence of a Driven Qubit
• Effective Field and the Bloch-Siegert Shift at Bihromatic Excitation of Multiphoton EPR

Cited by in corpus (5)

• TLS Dynamics in a Superconducting Qubit Due to Background Ionizing Radiation
• Enhancing the Coherence of Superconducting Quantum Bits with Electric Fields
• Identification of different types of high-frequency defects in superconducting qubits
• Stabilizing and improving qubit coherence by engineering noise spectrum of two-level systems
• Baseband control of superconducting qubits with shared microwave drives