Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Physical Review A

Pump-probe spectroscopy using quantum light with two-photon coincidence detection

Frank Schlawin, Konstantin E. Dorfman, Shaul Mukamel

Published Feb 3, 2016• 49 citations
Publisher

Abstract

We propose a pump-probe signal, whereby the sample is excited by a classical pulse, and---after a variable time delay---probed by a photon from an entangled pair, which is finally detected in coincidence with its twin. This setup offers an improved time and frequency resolution compared to a classical pump-probe signal, and can be used to enhance or suppress selected resonances.

DOI
10.1103/physreva.93.023807

Related papers

Multidimensional pump-probe spectroscopy with entangled twin-photon states

Oleksiy Roslyak, Shaul Mukamel

We show that entangled photons may be used in coherent multidimensional nonlinear spectroscopy to provide information on matter by scanning photon wave function parameters (entanglement time and delay of twin photons), rather than frequencies and time delays, as is commonly done with classical pulses. Signals are expressed and interpreted intuitively in terms of products of matter and field correlation functions using a diagrammatic close time path loop formalism which reveals the entangled quantum pathways of the fields and matter. The pump-probe signal measured when the pump and the probe are in a twin entangled state shows two-photon resonant contributions which scale linearly rather than quadratically with the incident beam intensity and reveal frequencies of off-resonant transitions. Two-dimensional spectrograms obtained by double Fourier transform of the signal with respect to the entanglement time and delay of the twins could provide detailed information on correlations among states and dynamical processes with high temporal resolution. The analogy with multidimensional time-domain optical techniques which use sequences of short classical pulses and pulse shaping algorithms is pointed out.

Physical Review A•Jun 17, 2009•69 citations

Entangled-photon time- and frequency-resolved optical spectroscopy

Raúl Álvarez-Mendoza, Lorenzo Uboldi, Ashley Lyons +3 more

Classical time-resolved optical spectroscopy experiments are performed using sequences of ultrashort light pulses, with photon fluxes incident on the sample which are many orders of magnitude higher than real-world conditions corresponding to sunlight illumination. Here we overcome this paradigm by exploiting quantum correlations to perform time-resolved spectroscopy with entangled photons. Starting from spontaneous parametric down-conversion driven by a continuous-wave laser, we exploit the temporal entanglement between randomly generated signal/idler pairs to obtain temporal resolution, and their spectral entanglement to select the excitation frequency. We also add spectral resolution in detection, using a Fourier transform approach which employs a common-path interferometer. We demonstrate the potential of our entangled-photon streak camera by resolving, at the single-photon level, excitation energy transfer cascades from LH2 to LH1 in the photosynthetic membrane and disentangling the lifetimes of two dyes in a mixture. We show that time-resolved spectroscopy with quantum light can be performed without compromising measurement time, recording a fluorescence time trace in less than a minute even for samples with low quantum yield, which can be reduced to sub-second times with acceptable signal-to-noise ratio. Our results provide a new approach to ultrafast optical spectroscopy, where experiments are performed under conditions comparable to real-world sunlight illumination.

arXiv:2505.02940•May 5, 2025•1 citation

Probing excited-state dynamics with quantum entangled photons: Correspondence to coherent multidimensional spectroscopy

Akihito Ishizaki

Quantum light is a key resource for promoting quantum technology. One such class of technology aims to improve the precision of optical measurements using engineered quantum states of light. In this study, we investigate transmission measurement of frequency-entangled broadband photon pairs generated via parametric down-conversion with a monochromatic laser. It is observed that state-to-state dynamics in the system under study are temporally resolved by adjusting the path difference between the entangled twin beams when the entanglement time is sufficiently short. The non-classical photon correlation enables time-resolved spectroscopy with monochromatic pumping. It is further demonstrated that the signal corresponds to the spectral information along anti-diagonal lines of, for example, two-dimensional Fourier-transformed photon-echo spectra. This correspondence inspires us to anticipate that more elaborately engineered photon states would broaden the availability of quantum light spectroscopy.

arXiv:2005.10982•The Journal of Chemical Physics•Aug 5, 2020•24 citations

Spectroscopy with Polarization Controlled Entangled Photons for Detecting Orbital Excitation in Solids

P Munkhbaatar, Duger Ulam-Orgikh, J Vanchinkhuu

We propose an excitation-probe measurement method utilizing entangled photon pulses. The excitation-probe signal is dominated by stimulated Raman scattering as well as two-photon absorption when the time delay between the excitation pulse and the probe pulse is shorter than the pulseduration. This paper demonstrates that the two-photon-absorption signal can be suppressed when the photons of the pulses are entangled. The stimulated Raman scattering signal can be composed of many peaks distributed over broad photon energies owing to the transitions between numerous quantum states in complex materials. We also show that the desired peaks among the many peaks can be selected by controlling the thickness of the nonlinear crystal, the pump pulse center frequency,and the polarization of the excitation pulse and probe pulse.

Физик сэтгүүл•Mar 13, 2022•0 citations

Emulating Quantum Entangled Biphoton Spectroscopy Using Classical Light Pulses

Liwen Ko, Robert L. Cook, K. Birgitta Whaley

= 0, 1, 2, ··· classical light pulses and an entangled photon pair (a biphoton state) where one photon acts as a reference without interacting with the matter sample, identical signals can be obtained by replacing the biphotons with classical-like coherent states of light, where these are defined explicitly in terms of the parameters of the biphoton states. An input-output formulation of quantum nonlinear spectroscopy is used to prove this equivalence. We demonstrate the equivalence numerically by comparing a classical pump-quantum probe experiment with the corresponding classical pump-classical probe experiment. This analysis shows that understanding the equivalence between entangled biphoton probes and carefully designed classical-like coherent state probes leads to quantum-inspired classical experiments that yield equivalent signals and provides insights for the future design of QLS experiments that could provide a true quantum advantage.

arXiv:2306.14424•The Journal of Physical Chemistry Letters•Aug 31, 2023•9 citations

Quantum-enhanced sensing of molecular excited-state dynamics with correlated photons

Jiahao Fan, Feihong Liu, Dangyuan Lei +2 more

Squeezed photons, which provide a quantum-correlated light with reduced noise, have emerged as a powerful resource for sensing the structures of matter. Here, we study the pump-probe scheme using squeezed photons whose spectral correlation of amplitudes can be tailored. A microscopic theory reveals a highly time-energy-resolved signal that is not attainable by classical pump-probe scheme. The results show high selectivity of accessing the molecular correlation functions, e.g., suppression of ground-state bleaching signal, and can significantly enhance signal intensity that surpasses the bottleneck by entangled twin photons. An application to a monolayer semiconductor model reveals a real-time monitoring of valley excitons and their dynamics, i.e., conversion between dark and bright excitons. We further show the intermediate squeezing regime-not strong squeezing-where time-resolved spectroscopy is favorable. Our work offers a paradigm for studying nonequilibrium dynamics of matter, in photocatalysis and optoelectronics.

Proceedings of the National Academy of Sciences•Oct 15, 2026•0 citations
We propose a pump-probe signal, whereby the sample is excited by a classical pulse, and---after a variable time delay---probed by a photon from an entangled pair, which is finally detected in coincidence with its twin. This setup offers an improved time and frequency resolution compared to a classical pump-probe signal, and can be used to enhance or suppress selected resonances.
We show that entangled photons may be used in coherent multidimensional nonlinear spectroscopy to provide information on matter by scanning photon wave function parameters (entanglement time and delay of twin photons), rather than frequencies and time delays, as is commonly done with classical pulses. Signals are expressed and interpreted intuitively in terms of products of matter and field correlation functions using a diagrammatic close time path loop formalism which reveals the entangled quantum pathways of the fields and matter. The pump-probe signal measured when the pump and the probe are in a twin entangled state shows two-photon resonant contributions which scale linearly rather than quadratically with the incident beam intensity and reveal frequencies of off-resonant transitions. Two-dimensional spectrograms obtained by double Fourier transform of the signal with respect to the entanglement time and delay of the twins could provide detailed information on correlations among states and dynamical processes with high temporal resolution. The analogy with multidimensional time-domain optical techniques which use sequences of short classical pulses and pulse shaping algorithms is pointed out.
Classical time-resolved optical spectroscopy experiments are performed using sequences of ultrashort light pulses, with photon fluxes incident on the sample which are many orders of magnitude higher than real-world conditions corresponding to sunlight illumination. Here we overcome this paradigm by exploiting quantum correlations to perform time-resolved spectroscopy with entangled photons. Starting from spontaneous parametric down-conversion driven by a continuous-wave laser, we exploit the temporal entanglement between randomly generated signal/idler pairs to obtain temporal resolution, and their spectral entanglement to select the excitation frequency. We also add spectral resolution in detection, using a Fourier transform approach which employs a common-path interferometer. We demonstrate the potential of our entangled-photon streak camera by resolving, at the single-photon level, excitation energy transfer cascades from LH2 to LH1 in the photosynthetic membrane and disentangling the lifetimes of two dyes in a mixture. We show that time-resolved spectroscopy with quantum light can be performed without compromising measurement time, recording a fluorescence time trace in less than a minute even for samples with low quantum yield, which can be reduced to sub-second times with acceptable signal-to-noise ratio. Our results provide a new approach to ultrafast optical spectroscopy, where experiments are performed under conditions comparable to real-world sunlight illumination.
Quantum light is a key resource for promoting quantum technology. One such class of technology aims to improve the precision of optical measurements using engineered quantum states of light. In this study, we investigate transmission measurement of frequency-entangled broadband photon pairs generated via parametric down-conversion with a monochromatic laser. It is observed that state-to-state dynamics in the system under study are temporally resolved by adjusting the path difference between the entangled twin beams when the entanglement time is sufficiently short. The non-classical photon correlation enables time-resolved spectroscopy with monochromatic pumping. It is further demonstrated that the signal corresponds to the spectral information along anti-diagonal lines of, for example, two-dimensional Fourier-transformed photon-echo spectra. This correspondence inspires us to anticipate that more elaborately engineered photon states would broaden the availability of quantum light spectroscopy.
We propose an excitation-probe measurement method utilizing entangled photon pulses. The excitation-probe signal is dominated by stimulated Raman scattering as well as two-photon absorption when the time delay between the excitation pulse and the probe pulse is shorter than the pulseduration. This paper demonstrates that the two-photon-absorption signal can be suppressed when the photons of the pulses are entangled. The stimulated Raman scattering signal can be composed of many peaks distributed over broad photon energies owing to the transitions between numerous quantum states in complex materials. We also show that the desired peaks among the many peaks can be selected by controlling the thickness of the nonlinear crystal, the pump pulse center frequency,and the polarization of the excitation pulse and probe pulse.
= 0, 1, 2, ··· classical light pulses and an entangled photon pair (a biphoton state) where one photon acts as a reference without interacting with the matter sample, identical signals can be obtained by replacing the biphotons with classical-like coherent states of light, where these are defined explicitly in terms of the parameters of the biphoton states. An input-output formulation of quantum nonlinear spectroscopy is used to prove this equivalence. We demonstrate the equivalence numerically by comparing a classical pump-quantum probe experiment with the corresponding classical pump-classical probe experiment. This analysis shows that understanding the equivalence between entangled biphoton probes and carefully designed classical-like coherent state probes leads to quantum-inspired classical experiments that yield equivalent signals and provides insights for the future design of QLS experiments that could provide a true quantum advantage.
Squeezed photons, which provide a quantum-correlated light with reduced noise, have emerged as a powerful resource for sensing the structures of matter. Here, we study the pump-probe scheme using squeezed photons whose spectral correlation of amplitudes can be tailored. A microscopic theory reveals a highly time-energy-resolved signal that is not attainable by classical pump-probe scheme. The results show high selectivity of accessing the molecular correlation functions, e.g., suppression of ground-state bleaching signal, and can significantly enhance signal intensity that surpasses the bottleneck by entangled twin photons. An application to a monolayer semiconductor model reveals a real-time monitoring of valley excitons and their dynamics, i.e., conversion between dark and bright excitons. We further show the intermediate squeezing regime-not strong squeezing-where time-resolved spectroscopy is favorable. Our work offers a paradigm for studying nonequilibrium dynamics of matter, in photocatalysis and optoelectronics.