The Calculation Of Static Electric Dipole Polarizability Of Strontium Atomic Optical Lattice Clock

At Present, accuracy for the SI second is currently defined by the caesium primarystandard. However, strontium atomic optical lattice clock have now achieved a lowersystematic uncertainty6.4×10-18, which is not only better than a single-ion-based clock,but also reduces the required measurement time by two orders of magnitude. Thissystematic uncertainty will become more accuracy and strontium atomic optical latticeclock will be expected to become a new generation of time and frequency standards, oncethe SI second has been redefined. To evaluate the systematic uncertainty and stability ofneutral strontium atomic, we need the highly accurate data of polarizabilities which comefrom the energy shifts in strontium atomic optical lattice clock. In this dissertation, on thebasis of the finite field method, to calculate and analyse the static electric dipolepolarizability of the ground state5s21S0and excited states5s5p3PJ(J=0,1,2) for thestrontium atomic optical lattice clock, the coupled cluster method of multiple referencestates is mainly used. The main contents of this dissertation are as follows:First of all, reviews the development of cold atomic clocks and cold atomic opticallattice clock, based on the superiority of strontium atomic optical lattice clock, theresearch situation of the static electric dipole polarizability of the ground state5s21S0andexcited states5s5p3PJ(J=0,1,2) for the strontium atomic are analyzed.Secondly, three kinds of calculation methods of electronic related energy in themany-body electronic system are introduced. Then, based on the finite-field method of thetheory of molecular polarization, the formula of static dipole polarizability of the groundstate5s21S0and the different components of scalar and tensor electric dipolepolarizabilities formula of excited states5s5p3PJ(J=0,1,2) are given for strontiumatomic optical lattice clock, the relationship of scalar and tensor electric dipolepolarizabilities between the uncoupled angular momentum representation and the coupledrepresentation are also obtained.Finally, on the basis of the DIRAC and MRCC softwares, considering the influenceof all electrons correlation effect and relativistic effect, the high precision energy shifts of the ground state5s21S0and excited state5s5p3PJ(J=0,1,2) for the strontium atomicoptical lattice clock are calculated with the relativistic multireference coupled clustermethod and the configuration interaction method. The corresponding static electric dipolepolarizabilities are obtained with the formula of polarizability in the finite field method.In this dissertation, through the calculations of static electric dipole polarizability ofthe ground state and the different components of scalar and tensor polarizabilities ofexcited states for the strontium atomic optical lattice clock, as the influence of electroncorrelation effect and relativistic effects laid a solid foundation in the high precisioncalculation of static electric dipole polarizability for strontium atomic and other heavyelements.