Neutral molecules are not electrified under any circumstances. When the neutral molecules collide with each other, the instantaneous electromagnetic property occurs due to the impact of the electrons of the outer layer (around the entire molecule).
Strong electromagnetic field
The neutral molecule is in a strong electric field, and its outer electrons are moved by the electric field, moving towards the direction opposite to the outer electric field direction (electron with negative charge), thereby Conductive, that is, it is broken.
Neutral molecules are in a strong magnetic field, which is the same as the orthographic speed of the same electrons in the outer magnetic field direction, and the rotation speed of the electrons in the direction of the outside magnetic field will become fast, resulting in an anti-magnetic force.
Part Long chain Organism macromolecule Due to the conjugate, only anti-magnetic properties, and conductivity, is a particular neutral molecule.
Neutral molecules Laser focusing and electrostatic guides
With great progress in laser cooling and imprisonment of neutral atoms, people receive cold atom samples with low temperatures A series of experiments such as BEC, primary chip, atomic laser, and radius of radius are achieved on this basis. Since the supernating molecule can be used for the study of basic physical problems, the basic physical constant precision measurement, molecular wavelet kinetic control, the experimental study of molecular cold collision properties, the improvement of optical frequency standard accuracy, super cooling molecular clock, no more Puller exhibition (ultra-high resolution) molecular spectroscopy, nonlinear ultra-cooling molecular spectroscopy, ultra-cooling molecule Raman spectroscopy, molecular material wave interferometry, nanolecular beam etching and development of nano-new materials, etc. . Therefore, there is a very important scientific significance and broad application prospects for the cooling of neutral molecules.
The basic conditions of laser cooling are: (1) There must be a simple multi-level system (such as a two-level or three-level system); (2) In this multi-level system, the photon "absorption-radiation" transition cycle must be closed; (3) This transition cycle process must be dissipated and can be repeated multiple times. Since the neutral atom is more stable in the resonance or near-resonance field, and the energy level is simple, the above laser cooling condition can be satisfied with the above-mentioned laser cooling conditions, and the effectiveness of the photon and atomic times during a large number of transition cycles. Exchange, resulting in a decrease in atomic motion velocity (atom temperature cooling), the atomic cooling temperature has reached about 0.5 nK.
Although laser prisoner has many successful experiments, the laser cooling of neutral molecules has not yet achieved breakthrough progress. The main reason: (1) Since the molecular energy level is quite complicated, even the simplest double atomic molecule, in addition to the electron energy level, there is a molecular vibration and rotation energy level, so it is difficult to use one or two laser beams. The repeated transition conditions of the above laser cooling requirements are met; (2) Since the resonance flu flu flu flu flu flu flu flu flu flu flu flu flu flu flu flu flu flu flu flu flu flu flu flu flu flu flu flu flu flu flu flu flu flu flu flu flu flu flu flu flu flu flu flu fluumane to photon is inevitably exchanged; (3) The molecules are easily scaveced in the near-resonant field, resulting in the instability of the molecule.
Focused hollow beam
When a bunch of hollow beams are focused, a Gaussian spot is formed due to the diffraction effect of the lens and the concentration of the focused light. However, if a bunch of Gauss beams and even a bunch of hollow beams are focused by a special 2π bit plate, the focus beam is not only hollow near the focus, but also due to the interference on the optical axis, the other parts of the beam are also Slide, thus such a beam is called a focused hollow beam. Because this hollow beam has a small DSS on its focal level, it can be used to focus on the atom beam (molecular beam) to form atom (molecular) lenses. Since the light intensity at the focus is quite large, there is a high intensity gradient near the H focus, so the laser cooling of the guide atom can be achieved by the SiSyphus intensity gradient, and can be used to study the cold atom in the focus empty beam. The process of adiabatic compression and adiabatic expansion.
The focus empty beam produced by 2π-bit plates has a large strength gradient near the focus, and the SiSyphus cooling effect produced in this blue-resistant focusing hollow beam will be more obvious, and this beam can also The heat-insulating compression and adiabatic expansion effect of cold atoms are studied; on the focal plane, the smaller the DSS of the focus hollow beam, the larger the optical potential, the larger the corresponding optimum distortion D, the more consequentially, the atomic lens. Because this is not only easy to get higher resolution atomic lenses, but also reduce spontaneous radiation and photon scattering effects of atoms in the air-heart beam. The molecules are greatly optically optically in the vicinity of the focus, and the light field dip is also much greater than the gravity of the molecule. When the average temperature of the molecule is relatively low, optical guidance, focus, imprisonment and control, and even constituent molecular lenses can be configured in the focus empty beam.
Electrostatic surface guidance
due to the STARK effect, the polar molecule will be moved by the electric field dip, this even greater force The extensive electric field strength is still pointing to the strength of the electric field strength, and it is completely dependent on the homogenic search state or a strong field search state. Therefore, the electrostatic guidance of polar molecules can be divided into two modes: the electrostatic guidance of the strong field search nominal molecule and the electrostatic guidance of the weak field search status molecule. Since the number of molecules on the Kepier track is very small, this molecular guidance is very small. However, the hollow electrostatic conduits generated by the surface of the insulating medium can lead to a polar molecule of the weak field search state along the Z direction, which can obtain a high guiding efficiency. When the half width A between the conductor rod is smaller, the radius r 0 is large, and when the distance B between the ground plane is small, the larger the guide voltage, the maximum horizontal effective prisoner W (Y) Effective , the larger the lateral constraint of the polar cold molecule, the average diameter of the cant molecule (i.e., the average lateral motion range) is cleared in the hollow electrostatic conduit.