$\text{Ab initio}$ evidence for nonthermal characteristics in ultrafast laser melting

Abstract

Laser melting of semiconductors has been observed for almost 40 years; surprisingly, it is not well understood where most theoretical simulations show a laser-induced thermal process. $\text{Ab initio}$ nonadiabatic simulations based on real-time time-dependent density functional theory reveal intrinsic nonthermal melting of silicon, at a temperature far below the thermal melting temperature of 1680 K. Both excitation threshold and time evolution of diffraction intensity agree well with experiment. Nonthermal melting is attributed to excitation-induced drastic changes in bonding electron density, and the subsequent decrease in the melting barrier, rather than lattice heating as previously assumed in the two-temperature models.

References in corpus (4)

• Nanoscale manipulation of the Mott insulating state coupled to charge order in 1T-TaS2
• Non-thermal separation of electronic and structural orders in a persisting charge density wave
• Thermal and nonthermal melting of silicon under femtosecond x-ray irradiation
• Femtosecond Laser Processing of Germanium: An Ab Initio Molecular Dynamics Study

Cited by in corpus (10)

• Ultrafast charge ordering by self-amplified exciton-phonon dynamics in TiSe${}_2$
• Hot Phonon and Carrier Relaxation in Si(100) Determined by Transient Extreme Ultraviolet Spectroscopy
• Photoexcitation Induced Quantum Dynamics of Charge Density Wave and Emergence of a Collective Mode in 1T-TaS${}_2$
• The seeds and homogeneous nucleation of photoinduced nonthermal melting in semiconductors due to self-amplified local dynamic instability
• Manipulating Weyl quasiparticles by orbital-selective photoexcitation in WTe2
• Momentum-resolved TDDFT algorithm in atomic basis for real time tracking of electronic excitation
• Energy relaxation and electron-phonon coupling in laser-excited metals
• Picosecond-scale Heterogeneous Melting of Metals at Extreme Non-equilibrium States
• Pausing ultrafast melting by timed multiple femtosecond-laser pulses
• A Unified Heterogeneous Implementation of Numerical Atomic Orbitals-Based Real-Time TDDFT within the ABACUS Package