Probing the Fluctuations of Optical Properties in Time-Resolved Spectroscopy.

We show that, in optical pump-probe experiments on bulk samples, the statistical distribution of the intensity of ultrashort light pulses after interaction with a nonequilibrium complex material can be used to measure the time-dependent noise of the current in the system. We illustrate the general arguments for a photoexcited Peierls material. The transient noise spectroscopy allows us to measure to what extent electronic degrees of freedom dynamically obey the fluctuation-dissipation theorem, and how well they thermalize during the coherent lattice vibrations. The proposed statistical measurement developed here provides a new general framework to retrieve dynamical information on the excited distributions in nonequilibrium experiments, which could be extended to other degrees of freedom of magnetic or vibrational origin.

[1]  L. Mandel.  Fluctuations of Photon Beams and their Correlations , 1958 .

[2]  G. Blatter,et al.  Statistics of radiation emitted from a quantum point contact , 2009, 0911.4676.

[3]  D. Mihailovic,et al.  Ultrafast optical spectroscopy of strongly correlated materials and high-temperature superconductors: a non-equilibrium approach , 2016, 1601.07204.

[4]  Subcycle quantum electrodynamics , 2016, Nature.

[5]  Titimbo Chaparro,et al.  CREATION AND DETECTION OF SQUEEZED PHONONS IN PUMP AND PROBE EXPERIMENTS: A FULLY QUANTUM TREATMENT , 2015 .

[6]  Counting statistics of photons produced by electronic shot noise. , 2000, Physical review letters.

[7]  J. Bonca,et al.  Thermalization after photoexcitation from the perspective of optical spectroscopy , 2015, 1509.08431.

[8]  Gorjan Alagic,et al.  #p , 2019, Quantum information & computation.

[9]  A. Karimi,et al.  Master‟s thesis , 2011 .

[10]  Hideo Aoki,et al.  Nonequilibrium dynamical mean-field theory and its applications , 2013, 1310.5329.

[11]  R. Kubo.  Statistical-Mechanical Theory of Irreversible Processes : I. General Theory and Simple Applications to Magnetic and Conduction Problems , 1957 .

[12]  P. Kelley,et al.  Theory of Electromagnetic Field Measurement and Photoelectron Counting , 1964 .

[13]  M. Kollar,et al.  Theory of time-resolved optical spectroscopy on correlated electron systems , 2008, 0808.1005.

[14]  J. Kirkwood.  The statistical mechanical theory of irreversible processes , 1949 .

[15]  M. Fleischhauer.  Quantum-theory of photodetection without the rotating wave approximation , 1998 .

[16]  Counting Statistics of Photons Produced by Electronic Shot Noise , 2005 .

[17]  O. Misochko.  Coherent phonons and their properties , 2001 .

[18]  I. Timrov,et al.  Direct observation of electron thermalization and electron-phonon coupling in photoexcited bismuth , 2013, 1802.00275.

[19]  F. Benatti,et al.  Generation and detection of squeezed phonons in lattice dynamics by ultrafast optical excitations , 2017 .

[20]  F. Benatti,et al.  Photon number statistics uncover the fluctuations in non-equilibrium lattice dynamics , 2015, Nature Communications.

[21]  I. Timrov,et al.  Thermalization of photoexcited carriers in bismuth investigated by time-resolved terahertz spectroscopy and ab initio calculations , 2012 .

[22]  Hideo Aoki,et al.  Interaction quench in the Holstein model: Thermalization crossover from electron- to phonon-dominated relaxation , 2014, 1407.8288.