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Buch ; Online: Terahertz radiation of jerk photocurrent

Mendoza, Bernardo S. / Fregoso, Benjamin M.

2020

Abstract: We compute the jerk current tensor of GaAs, Si, and ferroelectric single-layer GeS, GeSe, SnS, and SnSe. We find peak values of the order of $10^{14}$ mA/V$^3$s$^2$ in GaAs and Si within the visible energy spectrum and an order of magnitude larger in ... ...

Abstract	We compute the jerk current tensor of GaAs, Si, and ferroelectric single-layer GeS, GeSe, SnS, and SnSe. We find peak values of the order of $10^{14}$ mA/V$^3$s$^2$ in GaAs and Si within the visible energy spectrum and an order of magnitude larger in single-layer GeS, GeSe, SnSe and SnS. We show that the detailed knowledge of this tensor and its large value in single-layer GeS, GeSe, SnSe and SnS make it possible to predict the magnitude and angle of rotation of polarization of intense terahertz pulses generated in photoconductive switches and point to alternative functionalities of these devices. Comment: 9 pages, 8 figures, typos fixed, few errors corrected, conclusions unchanged, published version
Schlagwörter	Condensed Matter - Materials Science ; Physics - Optics
Erscheinungsdatum	2020-03-01
Erscheinungsland	us
Dokumenttyp	Buch ; Online
Datenquelle	BASE - Bielefeld Academic Search Engine (Lebenswissenschaftliche Auswahl)

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Artikel ; Online: Multipolar analysis of the second harmonic generated by dielectric particles.

Mandujano, Miguel A G / Méndez, Eugenio R / Valencia, Claudio I / Mendoza, Bernardo S

Optics express

2019 Band 27, Heft 3, Seite(n) 3337–3353

Abstract: We studied the second harmonic generation (SHG) by two-dimensional dielectric particles made of a centrosymmetric high-index material. The calculated scattered fields at the fundamental and harmonic frequencies are decomposed on a multipolar basis, ... ...

Abstract	We studied the second harmonic generation (SHG) by two-dimensional dielectric particles made of a centrosymmetric high-index material. The calculated scattered fields at the fundamental and harmonic frequencies are decomposed on a multipolar basis, allowing the evaluation of the relative strengths of the multipolar resonances excited at the particle. With these tools, we studied the strength of the multipoles that produce the second harmonic field and the role played by those excited at the fundamental frequency.
Sprache	Englisch
Erscheinungsdatum	2019-02-05
Erscheinungsland	United States
Dokumenttyp	Journal Article
ZDB-ID	1491859-6
ISSN	1094-4087 ; 1094-4087
ISSN (online)	1094-4087
ISSN	1094-4087
DOI	10.1364/OE.27.003337
Datenquelle	MEDical Literature Analysis and Retrieval System OnLINE

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Artikel ; Online: Two-Photon Excitation Spectroscopy of Silicon Quantum Dots and Ramifications for Bio-Imaging.

Furey, Brandon J / Stacy, Benjamin J / Shah, Tushti / Barba-Barba, Rodrigo M / Carriles, Ramon / Bernal, Alan / Mendoza, Bernardo S / Korgel, Brian A / Downer, Michael C

ACS nano

2022 Band 16, Heft 4, Seite(n) 6023–6033

Abstract: Two-photon excitation in the near-infrared (NIR) of colloidal nanocrystalline silicon quantum dots (nc-SiQDs) with photoluminescence also in the NIR has potential opportunities in the field of deep biological imaging. Spectra of the degenerate two-photon ...

Abstract	Two-photon excitation in the near-infrared (NIR) of colloidal nanocrystalline silicon quantum dots (nc-SiQDs) with photoluminescence also in the NIR has potential opportunities in the field of deep biological imaging. Spectra of the degenerate two-photon absorption (2PA) cross section of colloidal nc-SiQDs are measured using two-photon excitation over a spectral range 1.46 < ℏω < 1.91 eV (wavelength 850 > λ > 650 nm) above the two-photon band gap E<sub>g</sub><sup>(QD)</sup>/2, and at a representative photon energy ℏω = 0.99 eV (λ = 1250 nm) below this gap. Two-photon excited photoluminescence (2PE-PL) spectra of nc-SiQDs with diameters d = 1.8 ± 0.2 nm and d = 2.3 ± 0.3 nm, each passivated with 1-dodecene and dispersed in toluene, are calibrated in strength against 2PE-PL from a known concentration of Rhodamine B dye in methanol. The 2PA cross section is observed to be smaller for the smaller diameter nanocrystals, and the onset of 2PA is observed to be blue shifted from the two-photon indirect band gap of bulk Si, as expected for quantum confinement of excitons. The efficiencies of nc-SiQDs for bioimaging using 2PE-PL are simulated in various biological tissues and compared to efficiencies of other quantum dots and molecular fluorophores and found to be comparable or superior at greater depths.
Mesh-Begriff(e)	Silicon/chemistry ; Quantum Dots/chemistry ; Photons ; Nanoparticles/chemistry ; Spectrum Analysis
Chemische Substanzen	Silicon (Z4152N8IUI)
Sprache	Englisch
Erscheinungsdatum	2022-03-31
Erscheinungsland	United States
Dokumenttyp	Journal Article ; Research Support, U.S. Gov't, Non-P.H.S. ; Research Support, Non-U.S. Gov't
ISSN	1936-086X
ISSN (online)	1936-086X
DOI	10.1021/acsnano.1c11428
Datenquelle	MEDical Literature Analysis and Retrieval System OnLINE

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Artikel ; Online: Many-body perturbation theory and non-perturbative approaches: screened interaction as the key ingredient.

Tarantino, Walter / Mendoza, Bernardo S / Romaniello, Pina / Berger, J A / Reining, Lucia

Journal of physics. Condensed matter : an Institute of Physics journal

2018 Band 30, Heft 13, Seite(n) 135602

Abstract: Many-body perturbation theory is often formulated in terms of an expansion in the dressed instead of the bare Green's function, and in the screened instead of the bare Coulomb interaction. However, screening can be calculated on different levels of ... ...

Abstract	Many-body perturbation theory is often formulated in terms of an expansion in the dressed instead of the bare Green's function, and in the screened instead of the bare Coulomb interaction. However, screening can be calculated on different levels of approximation, and it is important to define what is the most appropriate choice. We explore this question by studying a zero-dimensional model (so called 'one-point model') that retains the structure of the full equations. We study both linear and non-linear response approximations to the screening. We find that an expansion in terms of the screening in the random phase approximation is the most promising way for an application in real systems. Moreover, by making use of the nonperturbative features of the Kadanoff-Baym equation for the one-body Green's function, we obtain an approximate solution in our model that is very promising, although its applicability to real systems has still to be explored.
Sprache	Englisch
Erscheinungsdatum	2018-03-02
Erscheinungsland	England
Dokumenttyp	Journal Article
ZDB-ID	1472968-4
ISSN	1361-648X ; 0953-8984
ISSN (online)	1361-648X
ISSN	0953-8984
DOI	10.1088/1361-648X/aaaeab
Datenquelle	MEDical Literature Analysis and Retrieval System OnLINE

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Buch ; Online: Im$\{\chi^{(3)}\}$ spectra of 110-cut GaAs, GaP, and Si near the two-photon absorption band edge

Furey, Brandon J / Barba-Barba, Rodrigo M. / Carriles, Ramon / Bernal, Alan / Mendoza, Bernardo S. / Downer, Michael C.

2021

Abstract: Spectra of the degenerate two-photon absorption coefficient $\beta(\omega)$, anisotropy parameter $\sigma(\omega)$, and dichroism parameter $\delta(\omega) = \big[\sigma(\omega) + 2\eta(\omega)\big]/2$ of crystalline 110-cut GaAs, GaP, and Si at 300 K ... ...

Abstract	Spectra of the degenerate two-photon absorption coefficient $\beta(\omega)$, anisotropy parameter $\sigma(\omega)$, and dichroism parameter $\delta(\omega) = \big[\sigma(\omega) + 2\eta(\omega)\big]/2$ of crystalline 110-cut GaAs, GaP, and Si at 300 K were measured using femtosecond pump-probe modulation spectroscopy over an excitation range in the vicinity of each material's half-band gap $E_g/2$ (overall $0.62 < \hbar \omega < 1.91$ eV, or $2000 > \lambda > 650$ nm). Together these three parameters completely characterize the three independent components of the imaginary part of the degenerate third-order nonlinear optical susceptibility tensor $\mathrm{Im}\{\chi^{(3)}_{abcd}(\omega)\}$. In direct-gap GaAs, these components peak at $\hbar \omega \approx 0.78 E_g$ which is close to the peak at $\hbar \omega = 0.71 E_g$ predicted by the Jones-Reiss phenomenological model. The dispersion is comparable to ab initio calculations. In indirect-gap GaP and Si, these components tend to increase with $\hbar \omega$ over our tuning range. In Si, the dispersion differs significantly from predictions of semi-empirical models and ab initio calculations do not account for transitions below the two-photon direct band gap, motivating further investigation. Kleinman symmetry was observed to be broken in all three materials. We also note anomalies observed and their possible origins, emphasizing the advantages of a 2-beam experiment in identifying the contribution of various nonlinear effects. Comment: 62 pages, 63 figures, 86 references. The following article has been accepted by J. Appl. Phys. After it is published, it will be found at https://aip.scitation.org/journal/jap; added references, changes to manuscript after peer review, minor changes to supplementary material, and typos corrected
Schlagwörter	Condensed Matter - Materials Science ; Physics - Optics
Thema/Rubrik (Code)	535
Erscheinungsdatum	2021-02-14
Erscheinungsland	us
Dokumenttyp	Buch ; Online
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Buch ; Konferenzbeitrag: Proceedings / 5th International Conference on Optics of Surfaces and Interfaces (OSI-V) : Léon, México, 26 - 30 May 2003

Mendoza, Bernardo S

(Physica status solidi : C, Conferences and critical reviews ; 0,8)

2003

Körperschaft	International Conference on Optics of Surfaces and Interfaces
Veranstaltung/Kongress	International Conference on Optics of Surfaces and Interfaces (5, 2003.05.26-30, Léon) ; OSI (5, 2003.05.26-30, Léon)
Verfasserangabe	guest ed.: Bernardo S. Mendoza
Serientitel	Physica status solidi : C, Conferences and critical reviews ; 0,8
Sprache	Englisch
Umfang	Getr. Zählung [ca. 180 S.], Ill., graph. Darst.
Verlag	Wiley-VCH
Erscheinungsort	Weinheim
Dokumenttyp	Buch ; Konferenzbeitrag
ISBN	3527404945 ; 9783527404940
Datenquelle	Katalog der Technische Informationsbibliothek Hannover

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Artikel ; Online: Large Bulk Photovoltaic Effect and Spontaneous Polarization of Single-Layer Monochalcogenides.

Rangel, Tonatiuh / Fregoso, Benjamin M / Mendoza, Bernardo S / Morimoto, Takahiro / Moore, Joel E / Neaton, Jeffrey B

Physical review letters

2017 Band 119, Heft 6, Seite(n) 67402

Abstract: We use a first-principles density functional theory approach to calculate the shift current and linear absorption of uniformly illuminated single-layer Ge and Sn monochalcogenides. We predict strong absorption in the visible spectrum and a large ... ...

Abstract	We use a first-principles density functional theory approach to calculate the shift current and linear absorption of uniformly illuminated single-layer Ge and Sn monochalcogenides. We predict strong absorption in the visible spectrum and a large effective three-dimensional shift current (∼100 μA/V^{2}), larger than has been previously observed in other polar systems. Moreover, we show that the integral of the shift-current tensor is correlated to the large spontaneous effective three-dimensional electric polarization (∼1.9 C/m^{2}). Our calculations indicate that the shift current will be largest in the visible spectrum, suggesting that these monochalcogenides may be promising for polar optoelectronic devices. A Rice-Mele tight-binding model is used to rationalize the shift-current response for these systems, and its dependence on polarization, in general terms with implications for other polar materials.
Sprache	Englisch
Erscheinungsdatum	2017-08-11
Erscheinungsland	United States
Dokumenttyp	Journal Article
ZDB-ID	208853-8
ISSN	1079-7114 ; 0031-9007
ISSN (online)	1079-7114
ISSN	0031-9007
DOI	10.1103/PhysRevLett.119.067402
Datenquelle	MEDical Literature Analysis and Retrieval System OnLINE

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Artikel ; Online: Efficient homogenization procedure for the calculation of optical properties of 3D nanostructured composites.

Mochan, W Luis / Ortiz, Guillermo P / Mendoza, Bernardo S

Optics express

2010 Band 18, Heft 21, Seite(n) 22119–22127

Abstract: We present a very efficient recursive method to calculate the effective optical response of metamaterials made up of arbitrarily shaped inclusions arranged in periodic 3D arrays. We apply it to dielectric particles embedded in a metal matrix with a ... ...

Abstract	We present a very efficient recursive method to calculate the effective optical response of metamaterials made up of arbitrarily shaped inclusions arranged in periodic 3D arrays. We apply it to dielectric particles embedded in a metal matrix with a lattice constant much smaller than the wavelength of the incident field, so that we may neglect retardation and factor the geometrical properties from the properties of the materials. If the conducting phase is continuous the low frequency behavior is metallic, and if the conducting paths are thin, the high frequency behavior is dielectric. Thus, extraordinary-transparency bands may develop at intermediate frequencies, whose properties may be tuned by geometrical manipulation.
Mesh-Begriff(e)	Algorithms ; Light ; Manufactured Materials ; Materials Testing ; Metals/chemistry ; Models, Statistical ; Nanocomposites/chemistry ; Nanostructures/chemistry ; Optics and Photonics ; Photons
Chemische Substanzen	Metals
Sprache	Englisch
Erscheinungsdatum	2010-10-11
Erscheinungsland	United States
Dokumenttyp	Journal Article ; Research Support, Non-U.S. Gov't
ZDB-ID	1491859-6
ISSN	1094-4087 ; 1094-4087
ISSN (online)	1094-4087
ISSN	1094-4087
DOI	10.1364/OE.18.022119
Datenquelle	MEDical Literature Analysis and Retrieval System OnLINE

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Buch ; Online: Two-Photon Excitation Spectroscopy of Silicon Quantum Dots and Ramifications for Bio-Imaging

Furey, Brandon J. / Stacy, Benjamin J. / Shah, Tushti / Barba-Barba, Rodrigo M. / Carriles, Ramon / Bernal, Alan / Mendoza, Bernardo S. / Korgel, Brian A. / Downer, Michael C.

2021

Abstract: Two-photon excitation in the near-infrared (NIR) of colloidal nanocrystalline silicon quantum dots (nc-SiQDs) with photoluminescence also in the NIR has the potential to open up new opportunities in the field of deep biological imaging. Spectra of the ... ...

Abstract	Two-photon excitation in the near-infrared (NIR) of colloidal nanocrystalline silicon quantum dots (nc-SiQDs) with photoluminescence also in the NIR has the potential to open up new opportunities in the field of deep biological imaging. Spectra of the degenerate two-photon absorption (2PA) cross section of colloidal nc-SiQDs are measured using two-photon excitation over a spectral range $1.46 < \hbar \omega < 1.91$ eV (wavelength $850 > \lambda > 650$ nm) above the two-photon band gap $E_g^{(QD)}/2$, and at a representative photon energy $\hbar \omega = 0.99$ eV ($\lambda = 1250$ nm) below this gap. Two-photon excited photoluminescence (2PE-PL) spectra of nc-SiQDs with diameters $d = 1.8 \pm 0.2$ and $d = 2.3 \pm 0.3$ nm, each passivated with 1-dodecene and dispersed in toluene, are calibrated in strength against 2PE-PL from a known concentration of Rhodamine B dye in methanol. The 2PA cross section is observed to be smaller for the smaller diameter nanocrystals and the onset of 2PA is observed to be blueshifted from the two-photon indirect band gap of bulk Si, as expected for quantum confinement of excitons. The efficiencies of nc-SiQDs for bio-imaging using 2PE-PL are simulated in various biological tissues and compared to other quantum dots and molecular fluorophores and found to be superior at greater depths. Comment: 35 pages, 21 figures, 79 references. The following manuscript was published in ACS Nano. This preprint is the submitted version. The peer-reviewed article can be found here: https://doi.org/10.1021/acsnano.1c11428
Schlagwörter	Physics - Applied Physics ; Condensed Matter - Materials Science ; Physics - Optics
Thema/Rubrik (Code)	530
Erscheinungsdatum	2021-12-22
Erscheinungsland	us
Dokumenttyp	Buch ; Online
Datenquelle	BASE - Bielefeld Academic Search Engine (Lebenswissenschaftliche Auswahl)

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Buch ; Online: Opto-electronic properties of alpha-In2Se3

Cho, Yujin / Anderson, Sean M. / Mendoza, Bernardo S. / Okano, Shun / Carriles, Ramon / Arzate, N. / Shkrebtii, Anatoli I. / Wu, Di / Lai, Keji / Zahn, D. R. T. / Downer, M. C.

single-layer to bulk

2019

Abstract: In this work, we report linear and non-linear spectroscopic measurements of chemically-grown layered (from one to 37 quintuple layers) and bulk alpha-In2Se3 samples over a photon energy range of 1.0--4 eV, and compare with ab initio density functional ... ...

Abstract	In this work, we report linear and non-linear spectroscopic measurements of chemically-grown layered (from one to 37 quintuple layers) and bulk alpha-In2Se3 samples over a photon energy range of 1.0--4 eV, and compare with ab initio density functional theory calculations, including bandstructures and G0W0 calculations. Comment: 10 pages, 7 figures
Schlagwörter	Condensed Matter - Materials Science ; Physics - Optics
Erscheinungsdatum	2019-11-05
Erscheinungsland	us
Dokumenttyp	Buch ; Online
Datenquelle	BASE - Bielefeld Academic Search Engine (Lebenswissenschaftliche Auswahl)

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