The tubular lipid membranes (TLMs) pulled out from vesicles are often used in in vitro studies of the interactions between curvature-inducing proteins and highly curved membranes. The protein molecules adsorbed at the membrane surface deform the TLM and couple with each other due to the induced strain. Here we propose an approach which models the single curvature-inducing protein action on the lipid bilayer by the multipole, the superposition of the point forces applied to the membrane in the region of the protein adsorption. We show that to be localized in the area of the protein size at the TLM surface, the force multipoles satisfying the mechanical equilibrium conditions should be composed of three or more point forces. The protein coupling energy mediated by the membrane strain is studied in detail. In the region of the tubular membrane stability the maximal distance between two neighboring interacting protein-induced force multipoles is estimated to be of the order of the TLM cross section perimeter. In the vicinity of the TLM instability in the region of the vanishing stretching force applied to the TLM, the interaction radius increases drastically. The high affinity of the single curvature-inducing protein molecule to the regions in the vicinity of the TLM ends is explained and related to the boundary conditions in the experimental set-ups. The reasons for the aggregate formation on the membrane surface are also discussed.

The nanometer-scale engineering of single nitrogen-vacancy (NV) centres in diamond can be obtained by low-energy (keV) nitrogen implantation with limited straggling. However, shallow NV centres (a few nanometres deep) generally have inferior overall properties than deeply implanted or deep native NV centres, due to the surface proximity. It has already been shown that the spin coherence time of shallow NVs is improved by overgrowth of a thin diamond layer. However the influence of the overgrowth on the survival, the optical properties and the charge state of the centres has not been studied in detail. In this article, we have overgrown three diamond samples (containing NV centres implanted at different depths) using different procedures. We show the successful overgrowth of a pattern of very shallow (2 nm) implanted NV centres using an optimised overgrowth process. Furthermore, the charge state of ensembles and single NV centres was found to be shifted from NV0 to NV− and stabilised in the negative charge state after overgrowth. The combination of low-energy high-resolution ion implantation and high-purity chemical vapour deposition (CVD) overgrowth procedures opens the way towards the fabrication of scalable and efficient quantum devices based on single defects in diamond.

We device plasmonic, bolometric and thermoelectric antenna-coupled Terahertz photodetectors based on black phosphorus and hybrid van der Walls heterostructures, showing 20000 signal to noise ratios and 100pW/Hz1/2 noise equivalent powers in the 0.3-3 THz frequency range.

Recent developments of THz detector arrays based on plasma wave field effect transistors are presented. By simultaneous development of the transistor arrays with their read-out circuits and diffractive 3D printed optics we demonstrate systems for imaging in 300 GHz atmospheric window with cameras or fast linear scanner. The first high speed THz postal scanner developed for real time fast A4 envelopes security screening is presented.

Design, manufacturing and measurements results for silicon plasma wave transistors based wireless communication wideband receivers operating at 300 GHz carrier frequency are presented. We show the possibility of Si-CMOS based integrated circuits, in which by: (i) specific physics based plasma wave transistor design allowing impedance matching to the antenna and the amplifier, (ii) engineering the shape of the patch antenna through a stacked resonator approach and (iii) applying bandwidth enhancement strategies to the design of integrated broadband amplifier, we achieve an integrated circuit of the 300 GHz carrier frequency receiver for wireless wideband operation up to/over 10 GHz. This is, to the best of our knowledge, the first demonstration of low cost 130 nm Si-CMOS technology, plasma wave transistors based fast/wideband integrated receiver operating at 300 GHz atmospheric window. These results pave the way towards future large scale (cost effective) silicon technology based terahertz wireless communication receivers.

Double-walled carbon nanotubes (DWCNT) are made of two concentric and weakly van der Waals coupled single-walled carbon nanotubes (SWCNT), also called layers. DWCNTs are the simplest systems for studying the mechanical and electronic interactions between concentric carbon layers. In this communication, we review recent results concerning the intrinsic features of phonons of DWCNTs obtained from Raman experiments performed on index-identified DWCNTs. The effect of the interlayer distance on the strength of the mechanical coupling between the layers, and thus on the frequencies of the Raman-active modes, namely the radial breathing-like modes (RBLM) [1] and G-modes [2], are evidenced and discussed.