The global-minimum structures of RuBn0/− (n = 9–20) clusters have been determined by the CALYPSO method combined with DFT calculations.

Beryllium-doped boron clusters display essential similarities to borophene (boron sheet) with a molecular structure characterized by remarkable properties, such as anisotropy, metallicity and high conductivity. Here we have determined low-energy structures of BeBn0/− (n = 10–20) clusters by utilizing CALYPSO searching program and DFT optimization. The results indicated that most ground states of clusters prefer plane or quasi-plane structures by doped Be atom. A novel unexpected fascinating planar BeB16− cluster with C2v symmetry is uncovered which possesses robust relative stability. Furthermore, planar BeB16− offers a possibility to construct metallo-borophene nano-materials. Molecular orbital and chemical bonding analysis reveal the peculiarities of BeB16− cluster brings forth the aromaticity and the strong interaction of B-B σ-bonds in boron network.

it will get entirely unusual derivatives with gratifying chemical bonding schemes for boron clusters by doping with lithium, the lightest alkalis. the geometric structures and electronic properties of the LiB n 0/− (n = 10−20) clusters have been studied through Crystal structure AnaLYsis by Particle Swarm Optimization (CALYPSO) structural search approach along with the density functional theory (DFT) calculations. the low-lying candidates of LiB n 0/− (n = 10-20) are reoptimized at the B3LYP functional in conjunction with 6-311 + G(d) basis set. Three forms of geometric configurations are identified for the ground-state structures of LiB n 0/− clusters: half-sandwich-type, quasi-planar and drum-type structures. The photoelectron spectra (PES) of the LiB n − clusters have been calculated through time-dependent density functional theory (TD-DFT). A promising LiB 13 with tetrahedral-typed B 13 ligand half-surround cluster and robust stability is uncovered. the molecular orbital and adaptive natural density partitioning (AdNDP) analysis show that B-B bonds in the B 13 moiety combined with the interaction between the B 13 shell and Li atom stabilize the C 2v LiB 13 cluster. our results advance the fundamental understanding about the alkali metal doped boron clusters.

We have developed a radio-frequency local oscillator remote distribution system, which transfers a phase-stabilized 10.03 GHz signal over 100 km optical fiber. The phase noise of the remote signal caused by temperature and mechanical stress variations on the fiber is compensated by a high-precision phase-correction system, which is achieved using a single sideband modulator to transfer the phase correction from intermediate frequency to radio frequency, thus enabling accurate phase control of the 10 GHz signal. The residual phase noise of the remote 10.03 GHz signal is measured to be -70  dBc/Hz at 1 Hz offset, and long-term stability of less than 1×10⁻¹⁶ at 10,000 s averaging time is achieved. Phase error is less than ±0.03π.

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Optical generation of highly stable millimeter and terahertz waves is proposed and experimentally demonstrated. The optical-fiber-path-induced phase fluctuation is identically transferred to a 40 MHz intermediate frequency by using dual-heterodyne phase error transfer, then canceled by a phase-locked loop. Based on the scheme, highly stable signals within the frequency range from 25 GHz to 1 THz are generated, and the phase jitter is decreased from 2.05 rad to 4.7 mrad in the frequency range from 0.01 Hz to 1 MHz. For 1 THz, the residual phase noise reaches -60  dBc/Hz at 1 Hz frequency offset from the carrier, and the relative timing jitter is reduced to 0.7 fs.

We report on a versatile optical frequency-modulated continuous-wave interferometry technique that exploits wideband phase locking for generating highly coherent linear laser frequency chirps. This technique is based on an ultra-short delay-unbalanced interferometer, which leads to a large bandwidth, short lock time, and robust operation even in the absence of any isolation from environmental perturbations. In combination with a digital delay-matched phase error compensation, this permits the achievement of a range window about 60 times larger than the intrinsic laser coherence length with a 1.25 mm Fourier transform-limited spatial resolution. The demonstrated configuration can be easily applied to virtually any semiconductor laser.

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