High-frequency acousto-optic deflector using ZnO thin films deposited on an amorphous substrate

Chang, Jiho; Harada, Nakahiro; Kashiwa, S.

doi:10.1049/el:19870955

Cited by 6 publications

(7 citation statements)

References 3 publications

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“…Cr-doped V 2 O 3 is the prototype Mott-Hubbard material [2][3][4], presenting a correlation-induced MIT without symmetry breaking. Strong electronic correlation split the noninteracting bands into interacting upper and lower Hubbard bands.…”

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confidence: 99%

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Surface Effects on the Mott-Hubbard Transition in ArchetypalV2O3

et al. 2015

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We present an experimental and theoretical study exploring surface effects on the evolution of the metal-insulator transition in the model Mott-Hubbard compound Cr-doped V{2}O{3}. We find a microscopic domain formation that is clearly affected by the surface crystallographic orientation. Using scanning photoelectron microscopy and x-ray diffraction, we find that surface defects act as nucleation centers for the formation of domains at the temperature-induced isostructural transition and favor the formation of microscopic metallic regions. A density-functional theory plus dynamical mean-field theory study of different surface terminations shows that the surface reconstruction with excess vanadyl cations leads to doped, and hence more metallic, surface states, which explains our experimental observations.

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confidence: 99%

“…In the metallic phase a strongly renormalized quasiparticle peak remains at the Fermi level which is reminiscent of the uncorrelated band structure. The phase diagram of V 2 O 3 consists of three phases: paramagnetic insulator (PI), paramagnetic metal (PM), and antiferromagnetic insulator (AFI) [2] (see Fig. 1 a)).…”

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confidence: 99%

Surface Effects on the Mott-Hubbard Transition in ArchetypalV2O3

et al. 2015

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“…1) which evoked several theoretical attempts to describe this MIT as a genuine Mott-Hubbard transition. While the MIT is associated to changes in the lattice structure and the atomic positions [3,4], it is important to notice that x-ray diffraction showed that for a given temperature the structure within one phase does not change upon doping [4]. It was later also observed by Park et al [5] with vanadium L-edge xray absorption spectroscopy that this holds also the electronic configuration of the system in terms of the orbital occupation (see Table 1 of [5]).…”

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confidence: 88%

Mott-Hubbard transition in V2O3 revisited

Hansmann,

Toschi,

Sangiovanni

et al. 2013

Preprint

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The isostructural metal-insulator transition in Cr-doped V 2 O 3 is the textbook example of a Mott-Hubbard transition between a paramagnetic metal and a paramagnetic insulator. We review recent theoretical calculations as well as experimental findings which shed new light on this famous transition. In particular, the old paradigm of a dopingpressure equivalence does not hold, and there is a microscale phase separation for Cr-doped V 2 O 3 .

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“…where T1, u and x are a components of the stress tensor, the particle displacement and the spatial direction, respectively, with the indices i and j labelling the spatial directions and summation over repeated indices has been implied. Equation (2) describes the electromagnetic wave properties of SAW, in which Maxwell' s equations govern the electric fields and electric displacements of SAW. Under a quasi-static approximation, the electric displacement equation in a medium of no free charges is given as:…”

Section: A Saw Perturbation On Quantum Well Structuresmentioning

confidence: 99%

Electro-absorptive and electro-optic quantum well modulators using surface acoustic wave

Choy¹,

Weiss

Li³

1998

SPIE Proceedings

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The characteristics of AI03Ga7As/GaAs QW acousto-absorption and acousto-optic modulators using the interaction between Surface Acoustic Wave (SAW) and quantum well (QW) optical waveguide structures are analyzed here theoretically. The QW structures are optimized by maximizing the optical confinement of modal field in the active region and the piezoelectric effect of SAW on QWs. The electric field induced by SAW reduces non-uniformly in depth, which limits in the development of high efficiency modulators, especially for devices with a large number of QWs in the active region. We present the results of the analysis of a range of QW SQW modulators using between one and 25 QWs in the active region. For devices with thin active regions, the QW structures are designed so that at the top surface strong SAW effects can be obtained while for the 25 periods structure, the QWs located at a depth of 2/3 SAW wavelength in order to obtain an uniform SAW induced electric field. The results show that the single and five QW devices are suitable for absorptive modulation and optical modulation respectively while the 25-QW modulators can shorten the modulation interaction length and thus increase modulation bandwidth. The effective index change of these devices are at least 10 times larger than the conventional surface acoustic wave devices. These results make the quantum-well modulators more attractive for the development of acousto-optic device applications.

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High-frequency acousto-optic deflector using ZnO thin films deposited on an amorphous substrate

Cited by 6 publications

References 3 publications

Surface Effects on the Mott-Hubbard Transition in ArchetypalV2O3

Surface Effects on the Mott-Hubbard Transition in ArchetypalV2O3

Mott-Hubbard transition in V2O3 revisited

Electro-absorptive and electro-optic quantum well modulators using surface acoustic wave

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