We investigate the influence of a well-defined reversible biaxial strain ≤ 0.12 % on the magnetization ( M ) of epitaxial ferromagnetic manganite films. M has been recorded depending on temperature, strain and magnetic field in 20 -50 nm thick films. This is

Tunable biaxial stresses, both tensile and compressive, are applied to a single layer graphene by utilizing piezoelectric actuators. The Gruneisen parameters for the phonons responsible for the D, G, 2D and 2D' peaks are studied. The results show that the D peak is composed of two peaks, unambiguously revealing that the 2D peak frequency (omega(2D)) is not exactly twice that of the D peak (omega(D)). This finding is confirmed by varying the biaxial strain of the graphene, from which we observe that the shift of omega(2D)/2 and omega(D) are different. The employed technique allows a detailed study of the interplay between the graphene geometrical structures and its electronic properties.

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We study the effect of an external biaxial stress on the light emission of single InGaAs/GaAs(001) quantum dots placed onto piezoelectric actuators. With increasing compression, the emission blueshifts and the binding energies of the positive trion (X+) and biexciton (XX) relative to the neutral exciton (X) show a monotonic increase. This phenomenon is mainly ascribed to changes in electron and hole localization and it provides a robust method to achieve color coincidence in the emission of X and XX, which is a prerequisite for the possible generation of entangled photon pairs via the recently proposed "time reordering" scheme.

Manganese oxides (R, A)MnO3 (R = La, Y, Bi or rare earth metal, A = non-trivalent doping element) have been one focus of research for two outstanding properties: (i) conduction electrons (if any) are highly spin-polarized and (ii) competing interactions of several electronic and lattice degrees of freedom lead to extremely rich phase diagrams and complex physics. A better understanding of the latter might result in future technologies using manganites in spin-electronic devices. This review attempts to systematically outline in a phenomenological approach some fundamentals and key experiments on ferromagnetic manganites, partially with respect to thin film structures. Macroscopic magnetic properties (of ferromagnets and glassy manganites) and intrinsic electron transport are described. Preparation and basic properties of thin films, followed by experiments on spin-polarized tunnelling are reviewed. Finally, multiferroic heteroepitaxial film systems of manganites and ferroelectric titanates are addressed, which are promising candidates for significant magnetoelectric phenomena at ambient temperatures.