Control of Elementary Excitations by Acoustic Fields

Electrically driven, coherent phonons (sound waves in solids) with frequencies in the super-high-frequency (SHF) 3-30 GHz range are an important tool for the coherent manipulation of solid-state excitations. These phonons play a crucial role in optomechanics by enabling processes such as laser...

Lasing – the emission of a collimated light beam of light with a well-defined wavelength (color) and phase - results from a self-organization process, in which a collection of emission centers synchronizes itself to produce identical light particles (photons). A similar self-organized...

Researchers from the Paul-Drude-Institut in Berlin, the Helmholtz-Zentrum in Dresden and the Ioffe Institute in St. Petersburg have demonstrated the use of elastic vibrations to manipulate the spin states of optically active color centers in SiC at room temperature. They show a non-trivial...

Non-reciprocal propagation of sound, that is, the different transmission of acoustic waves traveling along opposite directions, is an essential requirement for the realization of devices such as acoustic isolators and circulators. Here, we demonstrate the efficient non-reciprocal transmission of...

Straintronics is the research area where strain-induced physical effects are used to develop new technologies. Strain in graphene has been shown to give rise to various extraordinary phenomena. Here, we show that the vibrational properties of graphene can be locally modulated by the dynamic strain...

Light emission centres in solids are promising candidates for applications in quantum information processing due to their capability of acting as single photon sources. One of the challenges related to these kinds of quantum light sources is to find mechanisms for the efficient control of their...

Interactions of light and material excitations (e.g., excitons) are at the heart of the modern and future optoelectronics. Efficient control and spatial localization (confinement) of the optical fields and particles is a crucial challenge. The latter can be addressed by the strong coupling of the...

We have studied the lateral transport of electron spins in GaAs (111) quantum wells (QWs) under a transverse electric field E_z. A tightly focused (cf. Fig. 1a), circularly polarized laser beam generates a narrow ensemble of electron-hole (e-h) pairs with spins preferentially oriented along the...

The strain and piezoelectric potentials accompanying surface acoustic waves (SAWs) provide a powerful tool for the manipulation of elementary excitations (carriers, spins, excitons, flux quanta, etc.) in low-dimensional structures. In the case of a two-dimensional electron gas lying close to the...

Two main challenges for an efficient manipulation of the spin vector in semiconductors are the achievement of long electron spin coherence times as well as the development of spin manipulation techniques that do not compromise the spin lifetime. In III-V semiconductor quantum wells (QWs), the...