Signatures of atomic structure in subfemtosecond laser-driven electron dynamics in nanogaps

Laser-Driven Petahertz Electron Ratchet Nanobubbles

“…First, the electron current excites the electromagnetic fields, and the induced fields will reduce the currents. In an earlier work, we have studied this effect, and we estimate that the reduction of current would be a factor of 2 for the present structures. Second, coupling to phonons would also have a damping effect, but the time scale of this de-excitation is much longer than the time of the ratchet effect in the present work.…”

“…The generated timedependent electron current oscillates at petahertz frequencies and is modulated by the frequency of the driving laser. The operation of the device is based on the observation 20 that an oscillating laser pulse tends to drive a net electron flux from a sharp tip to a flat surface. We have envisioned a periodic system of "nanobubbles" facing each other with a sharp tip as it is shown in Figure 1.…”

The Exact Exchange-Correlation Potential in Time-Dependent Density Functional Theory: Choreographing Electrons with Steps and Peaks

“…XC [n(t)](r) which can be a useful analysis tool in cases where the exact groundstate xc potential can be computed (usually model 1D systems). Due to the lack of memory, the adiabatic approximation leads to large errors in some applications, sometimes failing completely [52][53][54][55][56][57][58][59][60], but in other cases it has been found to yield good predictions [5][6][7][8][9][10][11][12][13][14][15][16][17][18], even when the system is far from a ground-state. It is not completely understood why: possible reasons include, that the adiabatic approximation satisfies a number of exact conditions that are important in the time-dependent case [2], that in some applications a strong external field dominates over xc effects in driving the dynamics and that partial compensation of selfinteraction in the Hartree potential, even at the groundstate level, is enough, especially when the observables involve averaging over the details of the density distribution.…”

“…While perturbations around the ground-state yields a formalism for excited states, their couplings, and response, it is particularly the generality and practical efficiency of the real-time formulation that has led to the possibility of applications on large systems which could not be done otherwise, e.g. [5][6][7][8][9][10][11][12][13][14][15][16][17][18].…”

Size-dependent errors in real-time electron density propagation

“…Real-time TDDFT has been used to study electron (and nuclear) dynamics in a myriad of cases: multinucleon transfer reactions through molecular and atomic collisions, 1,2 molecules in oscillating electromagnetic fields of varying strengths, [3][4][5][6][7] high-harmonic generation, 8,9 resonant excitation dynamics (e.g. charge transfer, [10][11][12][13][14] excitation-energy transfer, 15 strong-field ionization, 16 core excitations, [17][18][19] plasmonic excitations 20 ), perturbations in organic, 21 biomolecules, 22 chiral molecules, 23,24 metallic [25][26][27] systems, periodic 28,29 systems, semiconductor materials, 30 optical cavities, 31 electronic stopping 32 etc. Runge and Gross 33 proved that there exists a one-to-one mapping between the time-dependent density of a system and the external potential, justifying the use of TDDFT to simulate time-dependent electronic phenomena.…”