Ultrafast Self‐Compton Cooling

Ultrafast Optimal Sideband Cooling under Non-Markovian Evolution.

A sideband cooling strategy that incorporates (i) the dynamics induced by structured (non-Markovian) environments in the target and auxiliary systems and (ii) the optimally time-modulated interaction between them is developed. For the context of cavity optomechanics, when non-Markovian dynamics are considered in the target system, ground state cooling is reached at much faster rates and at a mu...

Ultrafast carrier thermalization and cooling dynamics in few-layer MoS2.

Femtosecond optical pump-probe spectroscopy with 10 fs visible pulses is employed to elucidate the ultrafast carrier dynamics of few-layer MoS2. A nonthermal carrier distribution is observed immediately following the photoexcitation of the A and B excitonic transitions by the ultrashort, broadband laser pulse. Carrier thermalization occurs within 20 fs and proceeds via both carrier-carrier and ...

Clocking the Ultrafast Electron Cooling in Anatase Titanium Dioxide Nanoparticles

The recent identification of strongly bound excitons in roomtemperature anatase TiO2 single crystals and nanoparticles underscores the importance of bulk many-body effects in samples used for applications. Here, for the first time, we unravel the interplay between many-body interactions and correlations in highly excited anatase TiO2 nanoparticles using ultrafast twodimensional deep-ultraviolet...

Ultrafast cooling and heating scenarios for the laser-induced phase transition in CuO

Hot carrier cooling by acoustic phonons in epitaxial graphene by ultrafast pump-probe spectroscopy

We report the application nondegenerate ultrafast midinfrared spectroscopy to investigate the acoustic phonon cooling process in epitaxial graphene. We show that the powerdependent experimental results match theoretical predictions of the low temperature acoustic cooling process. The hot phonon effect in acoustic phonon cooling is observed experimentally, and a deformation potential of 30 eV ca...