吸附偶极分子的排列和取向

Topology of surfaces for molecular Stark energy, alignment and orientation generated by combined permanent and induced electric dipole interactions

We show that combined permanent and induced electric dipole interactions of polar and polarizable molecules with collinear electric fields lead to a sui generis topology of the corresponding Stark energy surfaces and of other observables - such as alignment and orientation cosines - in the plane spanned by the permanent and induced dipole interaction parameters. We find that the loci of the intersections of the surfaces can be traced analytically and that the eigenstates as well as the number of their intersections can be characterized by a single integer index. The value of the index, distinc…

Orientation-dependent hyperfine structure of polar molecules in a rare-gas matrix: a scheme for measuring the electron electric dipole moment

Because molecules can have their orientation locked when embedded into a solid rare-gas matrix, their hyperfine structure is strongly perturbed relative to the freely rotating molecule. The addition of an electric field further perturbs the structure, and fields parallel and antiparallel to the molecular orientation result in different shifts of the hyperfine structure. These shifts enable the selective detection of molecules with different orientations relative to the axes of a rare-gas crystal, which will be an important ingredient of an improved electron electric dipole moment measurement u…

Ultracold giant polyatomic Rydberg molecules: coherent control of molecular orientation

We predict the existence of a class of ultracold giant molecules formed from trapped ultracold Rydberg atoms and polar molecules. The interaction which leads to the formation of such molecules is the anisotropic charge-dipole interaction ($a/R^2$). We show that prominent candidate molecules such as KRb and deuterated hydroxyl (OD) should bind to Rydberg rubidium atoms, with energies $E_b\simeq 5-25$ GHz at distances $R\simeq 0.1-1 \ μ$m. These molecules form in double wells, mimicking chiral molecules, with each well containing a particular dipole orientation. We prepare a set of correlated dr…

Breakdown of the electric dipole approximation at Cooper minima in direct two-photon ionisation

We predict breakdown of the electric dipole approximation at nonlinear Cooper minimum in direct two-photon $K-$shell atomic ionisation by circularly polarised light. According to predictions based on the electric dipole approximation, we expect that tuning the incident photon energy to the Cooper minimum in two-photon ionisation results in pure depletion of one spin projection of the initially bound $1s$ electrons, and hence, leaves the ionised atom in a fully oriented state. We show that by inclusion of electric quadrupole interaction, dramatic drop of orientation purity is obtained. The low …

Aspects of arbitrarily oriented dipoles scattering in plane: short-range interaction influence

The impact of the short-range interaction on the resonances occurrence in the anisotropic dipolar scattering in a plane was numerically investigated for the arbitrarily oriented dipoles and for a wide range of collision energies. We revealed the strong dependence of the cross section of the 2D dipolar scattering on the radius of short-range interaction, which is modeled by a hard wall potential and by the more realistic Lennard-Jones potential, and on the mutual orientations of the dipoles. We defined the critical (magic) tilt angle of one of the dipoles, depending on the direction of the seco…

从K、Rb或Cs原子的永久电偶极矩寻找玻耳兹曼常量的新形式

New form of the Boltzmann constant from search for a permanent electric dipole moment of K, Rb or Cs atom

利用特殊的电容器，我们发现基态K、Rb或Cs原子是极性原子，具有与氢原子的激发态相同的eao（ao为玻尔半径）量级的大永久电偶极矩（EDM）。但我们不能用玻耳兹曼常量来计算原子的EDM。极性原子产生取向极化的机理与极性分子完全不同。极性分子（如HCl、H_2O等）的取向极化是指分子作为一个整体，在外场的作用下，其方向发生了偏转。与极性分子不同，极性原子，如K、Rb或Cs原子的取向极化，只是最外层的价电子，沿着高度椭圆的轨道，转向场的方向，但原子的其余部分并不运动！本文导出了玻耳兹曼常量的新形式。当应用于极性原子的取向极化时，其k值远小于1.38 × 10-23 J/K（如Cs原子的k=7.14 × 10-29 J/K）。当它应用于任何分子、非极性原子或极性原子的平移和振动时，其值k=1.38*10- 23 J/K。原因是原子核与分子或原子的其余部分一起运动。(see arXiv：0809.4767; arXiv：0810.0770; arXiv：0810.2026）