Measuring fluctuations in matter’s low-energy excitations is the key to unveiling the nature of the non-equilibrium response of materials.A promising outlook in this respect is offered by spectroscopic methods that a...Measuring fluctuations in matter’s low-energy excitations is the key to unveiling the nature of the non-equilibrium response of materials.A promising outlook in this respect is offered by spectroscopic methods that address matter fluctuations by exploiting the statistical nature of light-matter interactions with weak few-photon probes.Here we report the first implementation of ultrafast phase randomized tomography,combining pump-probe experiments with quantum optical state tomography,to measure the ultrafast non-equilibrium dynamics in complex materials.Our approach utilizes a time-resolved multimode heterodyne detection scheme with phase-randomized coherent ultrashort laser pulses,overcoming the limitations of phase-stable configurations and enabling a robust reconstruction of the statistical distribution of phase-averaged optical observables.This methodology is validated by measuring the coherent phonon response inα-quartz.By tracking the dynamics of the shot-noise limited photon number distribution of fewphoton probes with ultrafast resolution,our results set an upper limit to the non-classical features of phononic state inα-quartz and provide a pathway to access non-equilibrium quantum fluctuations in more complex quantum materials.展开更多
We present a novel approach to transient Raman spectroscopy,which combines stochastic probe pulses and a covariance-based detection to measure stimulated Raman signals in alpha-quartz.A coherent broadband pump is used...We present a novel approach to transient Raman spectroscopy,which combines stochastic probe pulses and a covariance-based detection to measure stimulated Raman signals in alpha-quartz.A coherent broadband pump is used to simultaneously impulsively excite a range of different phonon modes,and the phase,amplitude,and energy of each mode are independently recovered as a function of the pump-probe delay by a noisy-probe and covariance-based analysis.Our experimental results and the associated theoretical description demonstrate the feasibility of 2D-Raman experiments based on the stochastic-probe schemes,with new capabilities not available in equivalent mean-value-based 2D-Raman techniques.This work unlocks the gate for nonlinear spectroscopies to capitalize on the information hidden within the noise and overlooked by a mean-value analysis.展开更多
基金supported by the European Research Council through the project INCEPT(grant agreement no.677488)D.F.,E.M.R.,A.M.,and G.J.acknowledge the support of the Gordon and Betty Moore Foundation through the grant(CENTQC).
文摘Measuring fluctuations in matter’s low-energy excitations is the key to unveiling the nature of the non-equilibrium response of materials.A promising outlook in this respect is offered by spectroscopic methods that address matter fluctuations by exploiting the statistical nature of light-matter interactions with weak few-photon probes.Here we report the first implementation of ultrafast phase randomized tomography,combining pump-probe experiments with quantum optical state tomography,to measure the ultrafast non-equilibrium dynamics in complex materials.Our approach utilizes a time-resolved multimode heterodyne detection scheme with phase-randomized coherent ultrashort laser pulses,overcoming the limitations of phase-stable configurations and enabling a robust reconstruction of the statistical distribution of phase-averaged optical observables.This methodology is validated by measuring the coherent phonon response inα-quartz.By tracking the dynamics of the shot-noise limited photon number distribution of fewphoton probes with ultrafast resolution,our results set an upper limit to the non-classical features of phononic state inα-quartz and provide a pathway to access non-equilibrium quantum fluctuations in more complex quantum materials.
基金This work was supported by the European Commission through the European Research Council(ERC)Starting Grant Project“Inhomogenieties and Fluctuations in Quantum Coherent Matter Phases by Ultrafast Optical Tomography(INCEPT)”(Grant#677488)DF aknowledges the support of ERC Proof of Concept grant COBRAS(Grant#860365)+2 种基金This work has been performed using the LEGEND laser source made available by the Nanoscience Foundry and Fine Analysis(NFFA-MIUR Italy Progetti Internazionali)facilityS.M.C.gratefully acknowledges the support of the Alexander von Humboldt foundation through the Feodor Lynen programS.M.C.and S.M.gratefully acknowledge the support of the National Science Foundation(Grant CHE1953045).
文摘We present a novel approach to transient Raman spectroscopy,which combines stochastic probe pulses and a covariance-based detection to measure stimulated Raman signals in alpha-quartz.A coherent broadband pump is used to simultaneously impulsively excite a range of different phonon modes,and the phase,amplitude,and energy of each mode are independently recovered as a function of the pump-probe delay by a noisy-probe and covariance-based analysis.Our experimental results and the associated theoretical description demonstrate the feasibility of 2D-Raman experiments based on the stochastic-probe schemes,with new capabilities not available in equivalent mean-value-based 2D-Raman techniques.This work unlocks the gate for nonlinear spectroscopies to capitalize on the information hidden within the noise and overlooked by a mean-value analysis.
