Rotational Population Measurement of Ultracold 85Rb^133Cs Molecules in the Lowest Vibrational Ground State

We measure the rotational populations of ultracold SS Rbla3 Cs molecules in the lowest vibrational ground state by a depletion spectroscopy and quantify the molecular production rate based on the measurement of single ion signal area. The SSRb133Cs molecules in the X1∑＋（v = 0） are formed from the short-range （2）^3П0＋（V = 10, J = 0） molecular state. A home-made external-cavity diode laser is used as the depletion laser to measure the rotational populations of the formed molecules. Based on the determination of single ion signal, the production rates of molecules in the J=0 and J = 2 rotational levels are derived to be 4800mole/s and 7200mole/s, respectively. The resolution and quantification of molecules in rotational states are facilitative for the manipulation of rotational quantum state of ultracold molecules.

Production and Detection of Ultracold Ground State 85Rb133Cs Molecules in the Lowest Vibrational Level by Short-Range Photoassociation

We investigate the production of ultracold ground state x^1∑7＋（u = 0） RbCs molecules in the lowest vibrational level via short-range photoassociation followed by spontaneous emission. The starting point is the laser cooled 85Rb and laa cs atoms in a dual species, forced dark magneto-optical trap. The special intermediate level （5）O＋ （u = 10） correlated to the （2）311 electric state is achieved by the photoassociation process. The formed ground state X1∑＋ （u = 0） molecule is resonantly excited to the 2111 intermediate state by a 651 nm pulse laser and is ionized by a 532nm pulse laser and then detected by the time-of-flight mass spectrum. Saturation of the photoionization spectroscopy at large ionization laser energy is observed and the ionization efficiency is obtained from the fitting. The production of ultracold ground state 85Rblaacs molecules is facilitative for the further research about the manipulation of ultracold molecules in the rovibrational ground state.

AN SCF-CI STUDY OF HIGHLY EXCITED VIBRATIONAL STATES OF BENT TRIATOMIC MOLECULES AND ITS APPLICATION TO O_(3)

A self-consistent-field—configuration interaction(SCF-CI)procedure of studying highly excited vibrational states of bent triatomic molecules is suggested and its application to O_3 is investigated.

Effect of the reagent vibration on stereodynamics of the reaction O（^1D）＋HF→F＋OH

This paper studies the influence of the reagent vibration on the reaction O（1D）＋HF→HO＋F by using a quasiclassical trajectory method on the new ab initio 1A＇ ground singlet potential energy surface （Gomez-Carrasco et al 2007 Chem. Phys. Lett. 435 188 193）. The product angular distributions which reflect the vector correlation are calculated. Four polarization-dependent differential cross sections （PDDCSs） which are sensitive to many photoinitiated bimolecular reaction experiments are presented in the center of the mass frame, respectively. The differential cross section indicates that the OH product mainly tends to the forward scattering, and other PDDCSs are also influenced by the vibration levels of HF.

Transitional Description of Diatomic Molecules in U（4） Vibron Model

U(3)-O(4) transitional description of diatomic molecules in the U(4) vibron model is studied by usingthe algebraic Bethe ansatz, in which the O(4) limit is a special case of the theory. Vibrational band-heads of sometypical diatomic molecules are fitted by both transitional theory and the O(4) limit within the same framework. Theresults show that there are evident deviations from the O(4) limit in description of vibrational spectra of some diatomicmolecules.

Absorption Spectrum Studies on the RDX Crystals with Different Granularity in Terahertz Frequency Range

The absorption spectrum of the cyclotrime-thylenetrinitramine （RDX） with four different particle sizes are measured in the frequency range from 0.1THz to 2.5THz by using the terahertz time-domain spectroscopy （THz-TDS）, and the characteristic absorption peaks are acquired. All the samples are measured in a loose condition, which is very close to the real using environment of the RDX. The results show that the four kinds of samples have similar absorption peaks around the frequency of 0.82THz, 1.05 THz, 1.30THz, 1.46THz, 1.65THz, and 1.95THz. The sample with a large particle size obtains more peaks than the small one, while the peaks obtained from the sample with a small size are more protrudent. The reasons for these differences can be the refraction, scattering, and attenuation of the terahertz wave when it passes through the crystal samples. The theoretical terahertz spectrum of RDX was simulated by using density functional calculations, in which, the Becke ＆amp; Perdew-Wang＇s functional is used in a double numerical plus polarization method （BP/DNP）. Good agreements between the experimental and computed results show that the three peaks located in the frequency of 1.30THz, 1.48THz, and 1.96THz are caused respectively by the twisting of three-nitrogen heterocyclic, the symmetrical oscillations of the double nitro groups, and the oscillations of a single nitro group.

Metallic nanoparticles/graphene-molecules hybrid system-based active biosensor

The strong coupling between vibrational modes of molecules and surface plasmon resonance(SPR)modes in graphene makes them an ideal platform for biosensor techniques.In this paper,a new optical biosensor for molecule detection based on silver metallic nanoparticles(MNPs)and graphene/gold MNPs in a terahertz frequency range is achieved.It is established that the nonlinear electrical properties of graphene can play a major role in realizing a biosensor for molecule detection.The performance parameters of the proposed device are reported with respect to the chemical potential μ of graphene,noting that the sensitivity of our device passes from 255 nm/RIU(nanometers/refractive index unit)for μ=1.21 e V to 2753 nm/RIU for μ=0.21 e V.Finally,this structure exhibits an optical sensing region that can be adjusted to meet the requirements of optical detection.