The absorption of large bipolarons is investigated using the path-integral method. The response of a bipolaron to an external electromagnetic field is derived in the framework of the memory function approach. The bipolaron optical absorption spectrum consists of a series of relatively narrow peaks. The peculiarities of the bipolaron optical absorption as a function of the frequency of the elect...

Zusammenfassend kann gesagt werden, daß das Verhalten bei hohen Ladungsträgerdichten in beiden Arten der Untersuchungen auf den gleichen Grund zurückzuführen ist. Neben den Abhängigkeiten der effektiven Massen und der g-Faktoren von der Bänderform in der L A N D A U — P E I E R L S und PAULI-Suszeptibilität der Elektronen treten zusätzliche Interbandterme. die proport ional zur Ladungsträgerdichte

We calculate the optical conductivity in a clean system of quasiparticles coupled to charge-ordering collective modes. The absorption induced by these modes may produce an anomalous frequency and temperature dependence of lowenergy optical absorption in some cuprates. However, the coupling with lattice degrees of freedom introduces a nonuniversal energy scale leading to scaling violation in low...

Mass specific optical absorption coefficients of mineral dust components measured by a multi wavelength photoacoustic spectrometer N. Utry, T. Ajtai, M. Pintér, E. Tombácz, E. Illés, Z. Bozóki, and G. Szabó Department of Optics and Quantum Electronics, University of Szeged, Szeged, Hungary Hungarian Academy of Sciences on Photoacoustic Research Group, Szeged, Hungary Department of Physical Chem...

Graphyne and graphdiyne families of flat carbon (sp2/sp) networks with high degrees of π-conjunction are attracting much attention due to their promising electronic, optical, and mechanical properties. In the present investigation we have studied the structural, mechanical, electrical and optical properties of halogenated graphdiyne and graphyne. The optical spectra of pure and halog...

The effects of coherence of quantum transitions and the interference of resonant nonlinear optical processes on the spectra of absorption, amplification, and nonlinear-optical generation are considered. The most favorable conditions are discussed for the inversionless amplification, resonant refraction in the absence of absorption and for resonant enhancement of nonlinear-optical generation at ...

We present a theoretical calculation, within a continuum electron-phonon-coupled model, of the optical absorption due to polarons in polyacetylene [{CH),]. Our results can be applied to both transand cis-(CH)„, as well as potentially to other polymers (polypyroles, polyparaphenylenes) in which polarons are present. We establish that the essential signature of polaron absorption is the existence...

We have developed a technique which allows optical absorption measurements to be made using a pulsed light source and offers a sensitivity significantly greater than that attained using stabilized continuous light sources. The technique is based upon the measurement of the rate of absorption rather than the magnitude of absorption of a light pulse confined within a closed optical cavity. The de...

The optical band gap, extracted from absorption measurements, defines the figure of merit for transparent conducting oxides (TCOs). In many oxides, such as In O 2 3 or SnO2, inversion symmetry introduces a selection rule that blocks transitions from the valence-band maximum to the conduction-band minimum. This raises the absorption threshold and enlarges the optical gap relative to the fundamen...

Metal corrugated surfaces have the potential of enhancing optical absorption through surface plasmon (SP) excitation facilitated by light-metal interactions. The successful utilization of metal corrugation induced optical absorption can improve the response of free carrier absorption (FCA), based HEterojunction Interfacial Workfunction Internal Photoemission (HEIWIP) detectors. This article rep...