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Related papers: Negative free carrier absorption in terahertz quan…

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We consider terahertz absorption and gain in a single miniband of semiconductor superlattice subject to a bichromatic electric field in the most general case of commensurate frequencies of the probe and pump fields. Using an exact solution…

Mesoscale and Nanoscale Physics · Physics 2009-10-04 Alexey V. Shorokhov , Kirill N. Alekseev

Cooling down a trapped ion into its motional ground state is a central step for trapped ions based quantum information processing. State of the art cooling schemes often work under a set of optimal cooling conditions derived analytically…

Quantum Physics · Physics 2021-10-12 Xie-Qian Li , Shuo Zhang , Jie Zhang , Wei Wu , Chu Guo , Ping-Xing Chen

We determine the diffusion length of excess carriers in GaN by spatially resolved cathodoluminescence spectroscopy utilizing a single quantum well as carrier collector or carrier sink. Monochromatic intensity profiles across the quantum…

Harmonic frequency combs, in which the lasing modes are separated by a period of tens of free spectral ranges from each other, have been recently discovered in quantum cascade lasers (QCLs). There is an ongoing debate how the harmonic combs…

Optics · Physics 2020-08-05 Yongrui Wang , Alexey Belyanin

We develop the quantum theory of an open-cavity laser assuming that only two modes compete for gain. We show that the modes interact to build up a collective mode that becomes the lasing mode when pumping exceeds a threshold. This…

Quantum Physics · Physics 2011-08-26 V. Eremeev , S. E. Skipetrov , M. Orszag

Gain-switching laser diodes is a well-established technique for generating optical pulses with random phases, where the quantum randomness arises naturally from spontaneous emission. However, the maximum switching rate is limited by phase…

Here we perform a series of time-resolved experiments where a 100 fs pump pulse is tuned between 528 nm and 555 nm, across the second indirect gap of intrinsic silicon at ~540 nm which involves electrons in a higher-lying conduction band…

Optics · Physics 2017-01-24 Fabio Novelli , Jeffrey A Davis

Absorption refrigerators transfer thermal energy from a cold reservoir to a hot reservoir using input energy from a third, so-called work reservoir. We examine the operation of quantum absorption refrigerators when coherences between…

Mesoscale and Nanoscale Physics · Physics 2018-07-25 Michael Kilgour , Dvira Segal

We give an overview of our recent theoretical studies of the thermodynamics of excitons, and other solid-state qubits, driven by time-dependent laser fields. We consider a single such emitter and describe how the formation of strong-field…

Quantum Physics · Physics 2021-03-25 Paul R. Eastham , Conor Murphy

The temporal dynamics of charge carriers determines the speed with which electronics can be realized in condensed matter, and their direct manipulation with optical fields promises electronic processing at unprecedented petahertz…

In any quantum or wave system dissipation leads to decoherence. Therefore, it was surprising in first instance when experiments on strongly lossy random lasers showed unambiguously by measurements of the photon statistics and of the lasing…

Disordered Systems and Neural Networks · Physics 2012-03-28 Regine Frank , Andreas Lubatsch , Johann Kroha

We theoretically demonstrate that increase of absorption with constant gain in laser systems can lead to onset of laser generation. This counter-intuitive absorption induced lasing (AIL) is explained by emergence of additional lasing modes…

Optics · Physics 2023-07-19 I. A. Nechepurenko , D. G. Baranov , A. V. Dorofeenko

Hypersound Absorption of acoustic phonons having $ql>>1$ in a degenerate Carbon Nanotube (CNT) with linear energy dispersion near the Fermi level was theoretically studied. The general expression for the absorption coefficient ($\Gamma$)…

Mesoscale and Nanoscale Physics · Physics 2015-07-02 K. A. Dompreh , N. G. Mensah , S. Y. Mensah , S. S. Abukari , F. Sam , R. Edziah

Analytic expressions for the absorption coefficient (AC) of a weak electromagnetic wave (EMW) in 2D Graphene under influence of strong laser radiation are calculated using the quantum kinetic equation (QKE) in the case of electron-optical…

Mesoscale and Nanoscale Physics · Physics 2024-12-24 Anh-Tuan Tran , Nguyen Dinh Nama , Nguyen Thi Thanh Nhan , Nguyen Quang Bau

Recently much attention has being attracted to the problem of limitations on the attainable intensity of high power lasers [A.M. Fedotov {\it et al.} Phys. Rev. Lett. \textbf{105}, 080402 (2010)]. The laser energy can be absorbed by…

Plasma Physics · Physics 2011-03-23 E. N. Nerush , I. Yu. Kostyukov , A. M. Fedotov , N. B. Narozhny , N. V. Elkina , H. Ruhl

We develop a quantum model for the calculation of the gain of phonon-polariton intersubband lasers. The polaritonic gain arizes from the interaction between the electrons confined in a quantum well structure and the phonon confined in one…

Mesoscale and Nanoscale Physics · Physics 2018-04-12 Martin Franckié , Camille Ndebeka-Bandou , Keita Ohtani , Jérôme Faist

We present a robust and fast laser cooling scheme suitable for trapped atoms and ions. Based on quantum interference, generated by a special laser configuration, it is able to rapidly cool the system such that the final phonon occupation…

Quantum Physics · Physics 2010-01-28 J. Cerrillo , A. Retzker , M. B. Plenio

Scattering relativistic electrons with optical lasers can result in a significant frequency upshift for the photons, potentially producing $\gamma$-rays. This is what linear Compton scattering taught us. Ultra-intense lasers offer nowadays…

Plasma Physics · Physics 2019-06-05 Marija Vranic , Thomas Grismayer , Sebastian Meuren , Ricardo A. Fonseca , Luis O. Silva

We study the mechanical effects of light on an atom trapped in a harmonic potential when an atomic dipole transition is driven by a laser and it is strongly coupled to a mode of an optical resonator. We investigate the cooling dynamics in…

Quantum Physics · Physics 2007-09-05 Stefano Zippilli , Giovanna Morigi , Wolfgang P. Schleich

We propose a dynamic mechanism for the reversible regulation of photosynthesis in varying light environments. We employ a three-level quantum model to take into account the correlations between charge donors and charge acceptors immediately…

Biological Physics · Physics 2024-11-13 Guang Yang , Gen Tatara
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