A tunable time-resolved spontaneous Raman spectroscopy setup for probing ultrafast collective excitation and quasiparticle dynamics in quantum materials

Versteeg, R. B.; Zhu, Jingyi; Padmanabhan, Prashant; Boguschewski, C.; German, Raphael; Goedecke, M.; Becker, Petra; Loosdrecht, P.H.M. van

doi:10.1063/1.5037784

Cited by 22 publications

(17 citation statements)

References 83 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This dependence can be also used to trace down such adiabatic processes. For a realistic possibility of detecting these spectral features in time-resolved Raman spectroscopy one needs to face the limitations of the time-energy uncertainty [65]. For a time resolution of ∼ 50 fs, comparable with the pulse width, one gets a energy resolution of ∼ 36 meV.…”

mentioning

confidence: 99%

Ultrafast Hot Phonon Dynamics in MgB2 Driven by Anisotropic Electron-Phonon Coupling

et al. 2020

View full text Add to dashboard Cite

The zone-center E2g modes play a crucial role in MgB2, controlling the scattering mechanisms in the normal state as well the superconducting pairing. Here, we demonstrate via first-principles quantum-field theory calculations that, due to the anisotropic electron-phonon interaction, a hotphonon regime where the E2g phonons can achieve significantly larger effective populations than other modes, is triggered in MgB2 by the interaction with an ultra-short laser pulse. Spectral signatures of this scenario in ultrafast pump-probe Raman spectroscopy are discussed in detail, revealing also a fundamental role of nonadiabatic processes in the optical features of the E2g mode.Although MgB 2 is often regarded as a conventional high-T c superconductor, described by the Eliashberg theory for phonon-mediated superconductivity, it displays many peculiar characteristics that make it a unique case. Most remarkable is the anisotropy of the electronic and superconducting properties, where electronic states belonging to the σ bands are strongly coupled to phonons, and display thus large superconducting gaps ∆ σ , whereas electronic states associated with the π bands are only weakly coupled to the lattice, and hence exhibit small superconducting gaps ∆ π [1-10]. Such electronic anisotropy is also accompanied by a striking anisotropy in the phonon states. The electron-phonon (e-ph) coupling is indeed strongly concentrated in few in-plane E 2g phonons modes along the Γ − A path of the Brillouin zone [4,11,12], whereas the remaining e-ph coupling is spread over all other lattice modes in the Brillouin zone.Due to its pivotal role in ruling e-ph based many-body effects and in the superconducting pairing, the properties of the long-wavelength E 2g mode have been extensively investigated, both theoretically and experimentally [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30]. On the experimental side, Raman spectroscopy has proven particularly suitable for providing fundamental information on the lattice dynamics and on the manybody e-ph processes. Particularly debated is the origin of the large phonon linewidth Γ E2g ≈ 25 meV, and of the temperature dependence of both the phonon frequency and linewidth [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30]. The complexity of identifying the quantum-mechanical origin of these phenomena arises from the concomitance of the e-ph interaction, non-adiabaticity, and lattice anharmonicities, in turn responsible for phonon-phonon scattering and thermal expansion. A possible path for tuning selectively only one of these processes is thus highly desirable, in order to disentangle the different mechanisms in action.Ultrafast time-resolved optical characterizations of MgB 2 with a pump-probe setup were presented in Refs. [31][32][33], where two different relaxation times were identified in the normal states. In particular, the ob-served anomalous blueshift at a short time scale of the in-plane plasmon was qualitatively explained in Ref. [33] by assumin...

show abstract

mentioning

confidence: 99%

Ultrafast Hot Phonon Dynamics in MgB2 Driven by Anisotropic Electron-Phonon Coupling

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Time-resolved Raman scattering spectroscopy: Details of the time-resolved resonance Raman scattering spectroscopy method have been described elsewhere. [21,26] Briefly, an integrated ultrafast laser system (Light Conversion PHAROS) with two outputs of the fundamental 1030 14 nm pulses (compressed 300 fs and chirped 150 ps) pumps two optical parametric amplifiers (Light Conversion) to generate wavelength tunable laser pulses for selective excitation (~300 fs) and narrow-bandwidth laser pulses for Raman probing (~1.5 ps), respectively. The widely tunable pump pulse allows to cover a photon energy range from the near ultraviolet to the near infrared.…”

Section: Experimental Methodsmentioning

confidence: 99%

Unraveling the Excitonic Transition and Associated Dynamics in Confined Long Linear Carbon Chains with Time‐Resolved Resonance Raman Scattering

Zhu

Bernhardt

Cui

et al. 2021

Laser & Photonics Reviews

View full text Add to dashboard Cite

Long linear carbon chains are attracting intense interest arising from their remarkable properties, such as the tunable direct energy gap, the high mechanical hardness, and the high Raman response cross section, which would play a great role in their potential applications in future nanotechnology. Here the excitonic transitions and the associated relaxation dynamics of nanotube confined long linear carbon chains are comprehensively interrogated by using steady state and time‐resolved Raman spectroscopies. The exciton relaxation dynamics of the confined carbon chains occurs on a hundred of picoseconds timescale, in strong contrast to the host dynamics that occurs on a few picoseconds’ timescale. A prominent time‐resolved Raman response is observed over a broad energy range extending from 1.2 to 2.8 eV, which includes the strong Raman resonance region around 2.2 eV. Strong coupling between the chain and the nanotube host is found from the dynamics at high excitation energies which provides clear evidence for an efficient energy transfer from the host carbon nanotube to the chain. The experimental study presents the first unique characterization of the long linear carbon chain exciton dynamics, providing indispensable knowledge for the understanding of the interactions between different carbon allotropes.

show abstract

“…More direct and precise fingerprints have been proposed at the theoretical level in the analysis of time-resolved Raman spectroscopy, both in spectral features as well as in integrated spectral weights [36]. An accurate measurement of time-resolved Raman spectra in MgB 2 needs to face with the limitations of the uncertainty principle constraining time and energy resolution [45]. In addition, it should be remarked that in both cases the presence of a non-thermal population of the in-plane E 2g modes is not directly probed via the properties of the lattice degrees of freedom, but indirectly through the el-ph driven many-body renormalization of the electronic response, i.e.…”

Section: Introductionmentioning

confidence: 99%

Fingerprints of hot-phonon physics in time-resolved correlated quantum lattice dynamics

Cappelluti,

Novko

2021

Preprint

View full text Add to dashboard Cite

The time dynamics of the energy flow from electronic to lattice degrees of freedom in pump-probe setups could be strongly affected by the presence of a hot-phonon bottleneck, which can sustain longer coherence of the optically excited electronic states. Recently, hot-phonon physics has been experimentally observed and theoretically described in MgB 2 , the electron-phonon based superconductor with T c ≈ 39 K. By employing a combined ab-initio and quantum-field-theory approach and by taking MgB 2 as an example, here we propose a novel path for revealing the presence and characterizing the properties of hot phonons through a direct analysis of the information encoded in the lattice inter-atomic correlations. Such method exploits the underlying symmetry of the E 2g hot modes characterized by a out-of-phase in-plane motion of the two boron atoms. Since hot phonons occur typically at high-symmetry points of the Brillouin zone, with specific symmetries of the lattice displacements, the present analysis is quite general and it could aid in revealing the hot-phonon physics in other promising materials, such as graphene, boron nitride, or black phosphorus.

show abstract

A tunable time-resolved spontaneous Raman spectroscopy setup for probing ultrafast collective excitation and quasiparticle dynamics in quantum materials

Cited by 22 publications

References 83 publications

Ultrafast Hot Phonon Dynamics in MgB2 Driven by Anisotropic Electron-Phonon Coupling

Ultrafast Hot Phonon Dynamics in MgB2 Driven by Anisotropic Electron-Phonon Coupling

Unraveling the Excitonic Transition and Associated Dynamics in Confined Long Linear Carbon Chains with Time‐Resolved Resonance Raman Scattering

Fingerprints of hot-phonon physics in time-resolved correlated quantum lattice dynamics

Contact Info

Product

Resources

About