Dynamical decoupling and dephasing in interacting two-level systems

Abstract

We implement dynamical decoupling techniques to mitigate noise and enhance the lifetime of an entangled state that is formed in a superconducting flux qubit coupled to a microscopic two-level system. By rapidly changing the qubit's transition frequency relative to the two-level system, we realize a refocusing pulse that reduces dephasing due to fluctuations in the transition frequencies, thereby improving the coherence time of the entangled state. The coupling coherence is further enhanced when applying multiple refocusing pulses, in agreement with our $1/f$ noise model. The results are applicable to any two-qubit system with transverse coupling, and they highlight the potential of decoupling techniques for improving two-qubit gate fidelities, an essential prerequisite for implementing fault-tolerant quantum computing.

References in corpus (12)

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• Randomized Benchmarking of Quantum Gates
• Dynamical decoupling and noise spectroscopy with a superconducting flux qubit
• Coherent quantum state storage and transfer between two phase qubits via a resonant cavity
• Optimized Dynamical Decoupling in a Model Quantum Memory
• Decoherence of flux qubits due to 1/f flux noise
• Tackling Systematic Errors in Quantum Logic Gates with Composite Rotations
• Amplitude Spectroscopy of a Solid-State Artificial Atom
• Characterization of a two-transmon processor with individual single-shot qubit readout
• Quantum two-level systems in Josephson junctions as naturally formed qubits
• High-fidelity gates in a Josephson qubit
• Dynamical suppression of telegraph and 1/f noise due to quantum bistable fluctuator

Cited by in corpus (22)

• A Quantum Engineer's Guide to Superconducting Qubits
• 1/f noise: implications for solid-state quantum information
• Decoherence benchmarking of superconducting qubits
• Preserving entanglement and nonlocality in solid-state qubits by dynamical decoupling
• A General Transfer-Function Approach to Noise Filtering in Open-Loop Quantum Control
• Spurious harmonic response of multipulse quantum sensing sequences
• Improving quantum gate fidelities by using a qubit to measure microwave pulse distortions
• Protecting conditional quantum gates by robust dynamical decoupling
• Experimental quantum computational chemistry with optimised unitary coupled cluster ansatz
• Identification of different types of high-frequency defects in superconducting qubits
• Suppressing Coherent Two-Qubit Errors via Dynamical Decoupling
• Driven-state relaxation of a coupled qubit-defect system in spin-locking measurements
• Spin-echo entanglement protection from random telegraph noise
• Reconstruction-free quantum sensing of arbitrary waveforms
• Designing arbitrary single-axis rotations robust against perpendicular time-dependent noise
• High-fidelity two-qubit gates via dynamical decoupling of local 1/f noise at optimal point
• Protecting logical qubits with dynamical decoupling
• Protecting Superconducting Qubits with Universal Quantum Degeneracy Point
• Time-delayed quantum feedback and incomplete decoherence suppression with no-knowledge measurement
• Verification of a resetting protocol for an uncontrolled superconducting qubit
• Initial states of qubit-boson models leading to conserved quantities
• $T_1$-Echo Sequence - Protecting the state of a qubit in the presence of coherent interaction