Barium spectrum in high magnetic fields

Si:P as a laboratory analogue for hydrogen on high magnetic field white dwarf stars

“…NATURE COMMUNICATIONS | DOI: 10.1038/ncomms2466 ARTICLE both free atoms 1,15 and solids 28,29,[33][34][35]37,38 , its characteristic anti-crossings with Dm ¼ 0 and DL ¼ ± 2 have not been observed previously (and neither have the purely linear Zeeman, B>z anisotropy induced, anti-crossings with Dm ¼ ± 1 and DL ¼ 0). The results show that silicon donors provide an excellent laboratory material for studying effects of atomic physics that have previously been beyond the capability of laboratory equipment and available for study only in extreme astrophysical phenomena.…”

“…Identification of the observed spectral features is further hindered at these fields because the calculation of theoretical spectra where the magnetic cyclotron energy (:eB/m e ) is comparable to the coulombic binding energy (the Rydberg R ¼ m e e 4 /2k 2 : 2 , where k ¼ 4pe 0 ) is non-trivial, especially for atomic species other than hydrogen, such as helium [10][11][12] . The difficulty is that in the regime of interest (BBB 0 ¼ m e 2 e 3 /2k 2 : 3 ) the Zeeman effect becomes quadratic [13][14][15] , the spherical symmetry of the Coulomb potential competes with the cylindrical symmetry of the magnetic field, and the Schrodinger equation is non-integrable, so producing quantum chaos 16,17 . The theory for the very complex Zeeman structure in atoms has been compared with laboratory absorption spectra in magnetic fields up to 8 T (refs [13][14][15].…”

“…The difficulty is that in the regime of interest (BBB 0 ¼ m e 2 e 3 /2k 2 : 3 ) the Zeeman effect becomes quadratic [13][14][15] , the spherical symmetry of the Coulomb potential competes with the cylindrical symmetry of the magnetic field, and the Schrodinger equation is non-integrable, so producing quantum chaos 16,17 . The theory for the very complex Zeeman structure in atoms has been compared with laboratory absorption spectra in magnetic fields up to 8 T (refs [13][14][15]. Although in Rydberg atoms the cyclotron energy can be more easily made equivalent to the substantially lower binding energy (the characteristic field is lowered by a factor n 4 where n is the principal quantum number) 18 , the regime near B 0 is receiving renewed interest because it has recently been shown that a new kind of magnetic chemical bond can be produced that supersedes the electronic bond 19 , creating new molecules such as He 2 .…”

Core effect on the diamagnetic spectrum of barium Rydberg states

“…In the alkalineearth metals, the doubly excited states appear as prominent perturbation of the principal series in magnetic field [4,[14][15][16], or even in the absence of external fields [17,18], resulting in the quantum defect being energy dependent [19,20]. Therefore, * liuhongping@wipm.ac.cn there is a new possibility of competition between the electronic correlations and the external field which renders these spectra very interesting [21]. Typically, Fonck et al [14] observed the diamagnetic effect in 6s6p 1 P 1 −6sns 1 S 0 Rydberg series of barium in magnetic fields of 2-4 T and found that the perturbation of this series by the 5d7d 1 S 0 level reduces the shift below the hydrogenic value.…”

“…Lu et al [15] presented a densitometer mapping of diamagnetic effects on barium and strontium and discussed the effects of perturbation states (4d5p 1 P 1 for strontium and 5d8p 1 P 1 for barium) on the intensity and spacing of principle series spectra. The group of Connerade in Imperial College contributed much to the investigations of the diamagnetic effect of alkaline earths [21][22][23][24][25], giving a lot of inspiration to our work on the core scattering of the quadratic Zeeman spectrum of barium [26].…”