Quantum spectral analysis by continuous measurement of Landau-Zener transitions

Abstract

We demonstrate the simultaneous estimation of signal frequency and amplitude by a single quantum sensor in a single experimental shot. Sweeping the qubit splitting linearly across a span of frequencies induces a non-adiabatic Landau-Zener transition as the qubit crosses resonance. The signal frequency determines the time of the transition, and the amplitude its extent. Continuous weak measurement of this unitary evolution informs a parameter estimator retrieving precision measurements of frequency and amplitude. Implemented on radiofrequency-dressed ultracold atoms read out by a Faraday spin-light interface, we sense a magnetic signal with $20\text{pT}$ precision in amplitude, and near-transform-limited precision in frequency, in a single $300\text{ms}$ sweep from $7$ to $13\text{kHz}$. The protocol realizes a swept-sine quantum spectrum analyzer, potentially sensing hundreds or thousands of channels with a single quantum sensor.

7 pages, 2 figures, with 10 pages, 5 figures supplemental material

References in corpus (21)

• High-sensitivity diamond magnetometer with nanoscale resolution
• The Magnus expansion and some of its applications
• Sub-millihertz magnetic spectroscopy with a nanoscale quantum sensor
• Quantum sensing with arbitrary frequency resolution
• Dynamically Error-Corrected Gates for Universal Quantum Computation
• Single Ion Quantum Lock-In Amplifier
• Nonadiabatic Landau-Zener-Stückelberg-Majorana transitions, dynamics, and interference
• Quantum Phase Transitions and Continuous Observation of Spinor Dynamics in an Antiferromagnetic Condensate
• Simultaneous tracking of spin angle and amplitude beyond classical limits
• Heterodyne Sensing of Microwaves with a Quantum Sensor
• Single-Spin Spectrum-Analyzer for a Strongly Coupled Environment
• Achieving optimal quantum acceleration of frequency estimation using adaptive coherent control
• Quantum Diamond Radio Frequency Signal Analyser based on Nitrogen-Vacancy centers
• Synthetic clock transitions via continuous dynamical decoupling
• Majorana's approach to nonadiabatic transitions validates the adiabatic-impulse approximation
• Multiple shooting for training neural differential equations on time series
• Magic-wavelength Faraday probe measures spin continuously and without light shifts
• Phase sensitive quantum spectroscopy with high frequency resolution
• Continuously observing a dynamically decoupled spin-1 quantum gas
• Noise-resistant Landau-Zener sweeps from geometrical curves
• Spinsim: a GPU optimized python package for simulating spin-half and spin-one quantum systems