Single-Spin Spectrum-Analyzer for a Strongly Coupled Environment

Abstract

A qubit can be used as a sensitive spectrum analyzer of its environment. Here we show how the problem of spectral analysis of noise induced by a strongly coupled environment can be solved for discrete spectra. Our analytical model shows non-linear signal dependence on noise power, as well as possible frequency mixing, both are inherent to quantum evolution. This model enabled us to use a single trapped ion as a sensitive probe for strong, non-Gaussian, discrete magnetic field noise. To overcome ambiguities arising from the non-linear character of strong noise, we develop a three step noise characterization scheme: peak identification, magnitude identification and fine-tuning. Finally, we compare experimentally equidistant versus Uhrig pulse schemes for spectral analysis. The method is readily available to any quantum probe which can be coherently manipulated.

References in corpus (12)

• Dynamical decoupling and noise spectroscopy with a superconducting flux qubit
• Universal dynamical decoupling of a single solid-state spin from a spin bath
• Optimized Dynamical Decoupling in a Model Quantum Memory
• Fault-Tolerant Quantum Dynamical Decoupling
• How to Enhance Dephasing Time in Superconducting Qubits
• Single Ion Quantum Lock-In Amplifier
• Optimal Dynamical Decoherence Control of a Qubit
• Optimal pulse spacing for dynamical decoupling in the presence of a purely-dephasing spin-bath
• Universal dynamical decoherence control of noisy single-and multi-qubit systems
• Local observation of antibunching in a trapped Fermi gas
• Direct Measurement of the System-Environment Coupling as a Tool For Understanding Decoherence and Dynamical Decoupling
• Process tomography of dynamical decoupling in a dense optically trapped atomic ensemble