5 research outputs found
Quantum Regime of a Two-Dimensional Phonon Cavity
The quantum regime in acoustic systems is a focus of recent fundamental
research in the new field of Quantum Acoustodynamics (QAD). Systems based on
surface acoustic waves having an advantage of easy integration in
two-dimensions are particularly promising for the demonstration of novel
effects in QAD and development of novel devices of quantum acousto-electronics.
We demonstrate the vacuum mode of the surface acoustic wave resonator by
coupling it to a superconducting artificial atom. The artificial atom is
implemented into the resonator formed by two Brag mirrors. The results are
consistent with expectations supported by the system model and our
calculations. This work opens the way to map analogues of quantum optical
effects into acoustic systems
A phononic crystal coupled to a transmission line via an artificial atom
We study a phononic crystal interacting with an artificial atom { a
superconducting quantum system { in the quantum regime. The phononic crystal is
made of a long lattice of narrow metallic stripes on a quatz surface. The
artificial atom in turn interacts with a transmission line therefore two
degrees of freedom of different nature, acoustic and electromagnetic, are
coupled with a single quantum object. A scattering spectrum of propagating
electromagnetic waves on the artificial atom visualizes acoustic modes of the
phononic crystal. We simulate the system and found quasinormal modes of our
phononic crystal and their properties. The calculations are consistent with the
experimentally found modes, which are fitted to the dispersion branches of the
phononic crystal near the first Brillouin zone edge. Our geometry allows to
realize effects of quantum acoustics on a simple and compact phononic crystal
The Rationale for the Optimal Continuous-Variable Quantum Key Distribution Protocol
This article describes the current technical level of developments in the field of continuous-variable quantum key distribution (CV-QKD). Various classifications are described, the criteria are analyzed, and the optimal protocol is selected. The analysis is focused around device-dependent schemes with a theoretical emphasis, and therefore, a detailed analysis of device-independent CV-QKD and side-channel attacks is out of the scope of the work. However, the latter, one way or another, is taken into account when describing possible classifications. The choice of the optimal protocol was carried out, first of all, from the potential possibility of integration into existing network telecommunication infrastructures. Predominantly, the general classification is carried out in such a way that it is possible to draw up a specific protocol, depending on the task of implementation
Development of DNA aptamers for visualization of glial brain tumors and detection of circulating tumor cells
Here, we present DNA aptamers capable of specific binding to glial tumor cells in vitro, ex vivo, and in vivo for visualization diagnostics of central nervous system tumors. We selected the aptamers binding specifically to the postoperative human glial primary tumors and not to the healthy brain cells and meningioma, using a modified process of systematic evolution of ligands by exponential enrichment to cells; sequenced and analyzed ssDNA pools using bioinformatic tools and identified the best aptamers by their binding abilities; determined three-dimensional structures of lead aptamers (Gli-55 and Gli-233) with small-angle X-ray scattering and molecular modeling; isolated and identified molecular target proteins of the aptamers by mass spectrometry; the potential binding sites of Gli-233 to the target protein and the role of post-translational modifications were verified by molecular dynamics simulations. The anti-glioma aptamers Gli-233 and Gli-55 were used to detect circulating tumor cells in liquid biopsies. These aptamers were used for in situ, ex vivo tissue staining, histopathological analyses, and fluorescence-guided tumor and PET/CT tumor visualization in mice with xenotransplanted human astrocytoma. The aptamers did not show in vivo toxicity in the preclinical animal study. This study demonstrates the potential applications of aptamers for precise diagnostics and fluorescence-guided surgery of brain tumors.peerReviewe