Attosecond physics at the nanoscale

Abstract

Recently two emerging areas of research, attosecond and nanoscale physics, have started to come together. Attosecond physics deals with phenomena occurring when ultrashort laser pulses, with duration on the femto-and sub-femtosecond time scales, interact with atoms, molecules or solids. The laser-induced electron dynamics occurs natively on a timescale down to a few hundred or even tens of attoseconds (1 attosecond=1 as=10 −18 s), which is comparable with the optical field. For comparison, the revolution of an electron on a 1s orbital of a hydrogen atom is ∼ 152 as. On the other hand, the second branch involves the manipulation and engineering of mesoscopic systems, such as solids, metals and dielectrics, with nanometric precision. Although nano-engineering is a vast and well-established research field on its own, the merger with intense laser physics is relatively recent. In this report on progress we present a comprehensive experimental and theoretical overview of physics that takes place when short and intense laser pulses interact with nanosystems, such as metallic and dielectric nanostructures. In particular we elucidate how the spatially inhomogeneous laser induced fields at a nanometer scale modify the laser-driven electron dynamics. Consequently, this has important impact on pivotal processes such as above-threshold ionization and high-order harmonic generation. The deep understanding of the coupled dynamics between these spatially inhomogeneous fields and matter configures a promising way to new avenues of research and applications. Thanks to the maturity that attosecond physics has reached, together with the tremendous advance in material engineering and manipulation techniques, the age of atto-nano physics has begun, but it is in the initial stage. We present thus some of the open questions, challenges and prospects for experimental confirmation of theoretical predictions, as well as experiments aimed at characterizing the induced fields and the unique electron dynamics initiated by them with high temporal and spatial resolution.

Static Coherent States Method: One- and Two-Electron Laser-Induced Systems with Classical Nuclear Dynamics

“…in the ground state. We repeated the simulation with different laser intensities (from 0.1 × 10 14 to 2.0 × 10 14 W/cm 2 ). An interesting phenomenon that could happen at this point is the charge migration between the ground state and the first excited state of the system [8,40].…”

“…In the past two decades, the development of state-of-the-art technologies for generating and controlling ultra-short intense laser pulses has paved the way for more profound insights into electron and nuclear dynamics in atoms and molecules on their natural timescales [1][2][3][4][5]. Current theoretical treatments largely focus on electronic dynamics.…”

Spin-valley dynamics of electrically driven ambipolar carbon-nanotube quantum dots

“…driven by strong laser fields (for HHG from atomic or molecular sources see [22,23], for recent studies of HHG in solids see [24][25][26][27]). Higher harmonics of the driven dipole moment are found but only in resonant conditions.…”

Генерация Предельно-Коротких Импульсов При Возбуждении Нелинейной Резонансной Среды Световым Зайчиком, Движущимся Со Сверхсветовой Скоростью

“…Такие импульсы открыли воз-можность изучать и управлять динамикой сверхбыстрых процессов в веществе. Например, они позволяют осу-ществлять контроль динамики волновых пакетов в ато-мах, молекулах, твердых телах и наноструктурах [19][20][21][22]. Обычные генерируемые импульсы являются биполярны-ми, т. е. электрическая площадь таких импульсов (инте-грал от вектора напряженности электрического поля по времени в заданной точке пространства [23]) равен 0.…”

“…Однако в ряде ситуаций удается получить квазиуниполярные импульсы (КУИ), содержащие " всплеск" электрического поля и длинный хвост противоположной полярности, но меньшей ампли-туды. Очевидно, что такие импульсы представляют несо-мненный интерес ввиду возможности однонаправленно-го воздействия на электрические заряды и, следователь-но, перспективным является возможность применения таких импульсов для контроля динамики волновых паке-тов вещества [16][17][18][19][20][21][29][30]] и сверхбыстрого управления параметров резонансных сред, в частности решетками поляризации и разности заселенностей [31][32][33][34].505 …”