Coherent Light-Matter Interactions in Monolayer Transition-Metal Dichalcogenides PDF Download

Author: Edbert Jarvis Sie
Publisher: Springer
ISBN: 3319695541
Category : Science
Languages : en
Pages : 129

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Book Description
This thesis presents optical methods to split the energy levels of electronic valleys in transition-metal dichalcogenides (TMDs) by means of coherent light-matter interactions. The electronic valleys found in monolayer TMDs such as MoS2, WS2, and WSe2 are among the many novel properties exhibited by semiconductors when thinned down to a few atomic layers, and have have been proposed as a new way to carry information in next generation devices (so-called valleytronics). These valleys are, however, normally locked in the same energy level, which limits their potential use for applications. The author describes experiments performed with a pump-probe technique using transient absorption spectroscopy on MoS2 and WS2. It is demonstrated that hybridizing the electronic valleys with light allows one to optically tune their energy levels in a controllable valley-selective manner. In particular, by using off-resonance circularly polarized light at small detuning, one can tune the energy level of one valley through the optical Stark effect. Also presented within are observations, at larger detuning, of a separate contribution from the so-called Bloch--Siegert effect, a delicate phenomenon that has eluded direct observation in solids. The two effects obey opposite selection rules, enabling one to separate the two effects at two different valleys.

Author: Marcelo Ciappina
Publisher: World Scientific
ISBN: 9811279578
Category : Science
Languages : en
Pages : 352

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Book Description
'High-order harmonics emerging from the interaction of strong laser fields with solid matter constitute a novel, highly sensitive tool for interrogating electronic structure and dynamics in solids. At the interface of attosecond physics and condensed matter physics, this book provides an excellent overview of the current state of the art.'Ferenc KrauszNobel Laureate in Physics, 2023High-order harmonic generation (HHG) in solids, the nonlinear upconversion of coherent radiation resulting from the interaction of a strong and short laser pulse with bulk matter, has come of age. Since the seminal experiments and theoretical developments, there has been a constant and vibrant interest in this topic. In this book, we invite experimental and theoretical experts in the field with the aim to summarize the progress made so far and propose new possibilities and prospects for the generation of high-order harmonics using solid samples. Nowadays, it is possible to engineer, both spatially and temporally with nanometric and attosecond resolution, the driven fields. This could bring solid HHG to the next exciting frontier as novel and fully tunable table-top coherent sources.

Author: Bob D. Guenther
Publisher: Academic Press
ISBN: 0128149825
Category : Technology & Engineering
Languages : en
Pages : 2253

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Book Description
The Encyclopedia of Modern Optics, Second Edition, Five Volume Set provides a wide-ranging overview of the field, comprising authoritative reference articles for undergraduate and postgraduate students and those researching outside their area of expertise. Topics covered include classical and quantum optics, lasers, optical fibers and optical fiber systems, optical materials and light-emitting diodes (LEDs). Articles cover all subfields of optical physics and engineering, such as electro-optical design of modulators and detectors. This update contains contributions from international experts who discuss topics such as nano-photonics and plasmonics, optical interconnects, photonic crystals and 2D materials, such as graphene or holy fibers. Other topics of note include solar energy, high efficiency LED’s and their use in illumination, orbital angular momentum, quantum optics and information, metamaterials and transformation optics, high power fiber and UV fiber lasers, random lasers and bio-imaging. Addresses recent developments in the field and integrates concepts from fundamental physics with applications for manufacturing and engineering/design Provides a broad and interdisciplinary coverage of specialist areas Ensures that the material is appropriate for new researchers and those working in a new sub-field, as well as those in industry Thematically arranged and alphabetically indexed, with cross-references added to facilitate ease-of-use

Author: Jonghwan Kim
Publisher:
ISBN:
Category :
Languages : en
Pages : 71

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Book Description
Recently, atomically thin 2D materials have emerged as a new class of nanomaterial with extraordinary physical properties ranging from semi-metal (graphene), semiconductors (transition metal dichalcogenides) to insulators (hBN). Due to its unusual linear electronic spectrum, graphene has been studied as a platform where exotic quantum mechanical phenomena take place and electro-optical property can be greatly tuned by electrostatic gating. On the other hand, in semiconducting transition metal dichalcogenides (TMD), many body particles such as exciton and trion can be readily accessed even at room temperature due to strong Coulomb interaction. There are further exciting opportunities in heterostructures where layer-layer interaction provides new physics and functionalities. In this thesis, I explore light-matter interaction in 2D materials and their heterostructure with laser spectroscopy techniques. First of all, I study electromagnetic interaction between graphene and optical cavity via Rayleigh scattering spectroscopy. Although light-matter interaction in graphene is extremely strong for atomically thin thickness, overall optical response in macroscopic scale is still limited. Combination of graphene and resonant cavity can amplify the interaction dramatically. Therefore, it is important to understand the electromagnetic interaction between two systems. In this study, I find that the coupling can be explained by real and imaginary part of graphene dielectric constant which affects cavity resonance frequency and quality factor, respectively. In addition to fundamental interest, it also shows that this platform has promising potential for novel sensing application and electro-optical modulator. Secondly, I study valley-selective dipole interaction of exciton states in a monolayer transition metal dichalcogenides. Due to crystal symmetry, an extra degree of freedom, valley state, is available in this system. In analogy to spin state, it is important to understand and manipulate valley state with light. In this study, I demonstrate that valley excitonic states in a monolayer WSe2 can be manipulated by femtosecond pulse with the control of polarization. Ultrafast pump-probe spectroscopy shows that circularly-polarized femtosecond pulse induces valley-selective optical Stark effect which acts as a pseudomagnetic field. This demonstrates efficient and ultrafast control of the valley excitons with optical light, and opens up the possibility to coherent manipulate the valley polarization for quantum information applications. Lastly, I study interlayer interaction in heterostructure of MoS2/WS2 where strong exciton binding energy plays an important role. Simple band theory predicts that a heterostructure of two different semiconducting TMD layers forms type-II heterostructure. However, it is not clear how strong Coulomb interaction plays a role in terms of charge transfer dynamics. In this study, I demonstrate ultrafast charge transfer in MoS2/WS2 via both photoluminescence mapping and femtosecond (fs) pump-probe spectroscopy. Despite large exciton binding energy, hole transfer from the MoS2 layer to the WS2 layer takes place within 50 fs after optical excitation. Such ultrafast charge transfer in van der Waals heterostructures indicates that it can enable novel 2D devices for optoelectronics and light harvesting.

Author: Associate Professor Hebin Li
Publisher: Oxford University Press
ISBN: 0192843869
Category : Science
Languages : en
Pages : 305

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Book Description
This book provides an introduction to optical multidimensional coherent spectroscopy, a relatively new method of studying materials based on using ultrashort light pulses to perform spectroscopy. The technique has been developed and perfected over the last 25 years, resulting in multiple experimental approaches and applications to a broad array of systems ranging from atoms and molecules to solids and biological systems. Indeed, while this method is most often used by physical chemists, it is also relevant to materials of interest to physicists, which is the primary focus of this book. As well as an introduction to the method, the book also provides tutorials on the interpretation of the rather complex spectra that is broadly applicable across all subfields, and finishes with a survey of several emerging material systems and a discussion of future directions.

Author: Song Sun
Publisher: CRC Press
ISBN: 1000772594
Category : Technology & Engineering
Languages : en
Pages : 444

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Book Description
Driven by continuing pursuits in device miniaturization and performance improvement, emergent micro- and nanomaterials hold the keys to enabling next-generation technologies in optical, infrared, and terahertz applications, owing to their unique properties and strong responses in these frequency bands. Development of these fascinating materials has triggered a number of opportunities in the applied sciences, and some have even made their impact in the market. Emergent Micro- and Nanomaterials for Optical, Infrared, and Terahertz Applications reviews state-of-the-art developments in various emergent materials and their implementation in applications such as sensors, waveplates, communications, and light sources, among others. The book discusses the similarities, advantages, and limitations and offers a comparative of each material. This volume: Covers all emergent materials (natural and artificial) that are promising for optical, infrared, and terahertz applications Comparatively analyzes these materials, elucidating their unique advantages, limitations, and application scopes Provides an up-to-date record on achievements and progress in cutting-edge optical, infrared, and terahertz applications Offers a comprehensive overview to connect multidisciplinary fields, such as materials, physics, and optics, to serve as a basis for future progress This book is a valuable reference for engineers, researchers, and students in the areas of materials and optics, as well as physics, and will benefit both junior- and senior-level researchers.

Author: Chandriker Kavir Dass
Publisher:
ISBN:
Category :
Languages : en
Pages : 264

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Book Description
Two-dimensional semiconductors have long been studied for their unique optical and electronic properties, but with the work of Novoselov and Geim on van der Waals materials, two-dimensional semiconductors have seen a surge of renewed interest. This dissertation focuses on monolayer transition metal dichalcogenides (TMDCs), a class of two-dimensional materials that can easily be fabricated by mechanical exfoliation, much like graphene. In their bulk form, these materials have indirect band gaps, but transition to direct gap semiconductors in the monolayer limit. The band-edge optical response of TMDCs, like WSe2 and MoS2, is dominated by exciton absorption occurring at the ±K-points of the Brillouin zone. Because of the unique electronic structure of these materials, these two points form distinct valleys in the band structure which can be exploited to produce valley polarization. Exciton quantum dynamics are characterized by two fundamental parameters, one of which is the dephasing rate, [gamma], which describes quantum dissipation arising from the interaction of the excitons with their environment (i.e. other excitons, impurities, etc...). This dissertation focuses on measuring the fundamental property of dephasing time (which is inversely proportional to the dephasing rate and homogeneous linewidth) in monolayer WSe2 through the use of two-dimensional coherent spectroscopy. Our measurements have revealed a homogeneous linewidth consistent with dephasing times in the sub-picosecond regime. We also characterize the role of exciton-exciton and exciton-phonon interactions, on the homogeneous linewidth, through excitation density and temperature dependent studies. These studies have revealed strong many-body effects and nonradiative population relaxation as the primary dephasing mechanisms. Microscopic calculations show that in perfect crystalline samples of monolayer TMDCs, the radiative lifetimes are also in the sub-picosecond regime due to the large oscillator strengths inherent in these materials. This result is consistent with the short dephasing times found experimentally.

Author: Arash Rahimi-Iman
Publisher: Springer Nature
ISBN: 303069352X
Category : Science
Languages : en
Pages : 288

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Book Description
This book introduces the wider field of functional nanomaterials sciences, with a strong emphasis on semiconductor photonics. Whether you are studying photonic quantum devices or just interested in semiconductor nanomaterials and their benefits for optoelectronic applications, this book offers you a pedagogical overview of the relevant subjects along with topical reviews. The book discusses different yet complementary studies in the context of ongoing international research efforts, delivering examples from both fundamental and applied research to a broad readership. In addition, a hand-full of useful optical techniques for the characterization of semiconductor quantum structures and materials are addressed. Moreover, nanostructuring methods for the production of low-dimensional systems, which exhibit advantageous properties predominantly due to quantum effects, are summarized. Science and engineering professionals in the interdisciplinary domains of nanotechnology, photonics, materials sciences, and quantum physics can familiarize themselves with selected highlights with eyes towards photonic applications in the fields of two-dimensional materials research, light–matter interactions, and quantum technologies.

Author: Arash Rahimi-Iman
Publisher: Springer Nature
ISBN: 303039333X
Category : Science
Languages : en
Pages : 291

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Book Description
This book offers an overview of polariton Bose–Einstein condensation and the emerging field of polaritonics, providing insights into the necessary theoretical basics, technological aspects and experimental studies in this fascinating field of science. Following a summary of theoretical considerations, it guides readers through the rich physics of polariton systems, shedding light on the concept of the polariton laser, polariton microcavities, and the technical realization of optoelectronic devices with polaritonic emissions, before discussing the role of external fields used for the manipulation and control of exciton–polaritons. A glossary provides simplified summaries of the most frequently discussed topics, allowing readers to quickly familiarize themselves with the content. The book pursues an uncomplicated and intuitive approach to the topics covered, while also providing a brief outlook on current and future work. Its straightforward content will make it accessible to a broad readership, ranging from research fellows, lecturers and students to interested science and engineering professionals in the interdisciplinary domains of nanotechnology, photonics, materials sciences and quantum physics.

Author: Babak Anasori
Publisher: Springer Nature
ISBN: 3030190269
Category : Technology & Engineering
Languages : en
Pages : 534

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Book Description
This book describes the rapidly expanding field of two-dimensional (2D) transition metal carbides and nitrides (MXenes). It covers fundamental knowledge on synthesis, structure, and properties of these new materials, and a description of their processing, scale-up and emerging applications. The ways in which the quickly expanding family of MXenes can outperform other novel nanomaterials in a variety of applications, spanning from energy storage and conversion to electronics; from water science to transportation; and in defense and medical applications, are discussed in detail.