Valence ab initio calculation of the potential energy curves for the Sr2 dimer

Czuchaj, E.; Krośnicki, M.; Stoll, Hermann

doi:10.1016/s0009-2614(03)00268-9

Cited by 41 publications

(55 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…While the short-range potential energy structure for a molecule like Sr 2 is very complex for the excited states [63,64], we will now show that scattering length differences among different combinations of nuclear spin projections for the same Ω = 0 potential are expected to be very small. The scattering length a can be computed as a =ā[1 − tan(Φ − π/8)], whereā is the average scattering length governed by the asymptotic behavior of the potential and Φ is the semiclassical phase computed at zero energy from the classical turning point R 0 to infinity:…”

Section: Nuclear-spin Independence Of the Scattering Lengthsmentioning

confidence: 69%

“…[63,64] 87 Sr. This yields the following estimate for the dependence of a gg on the nuclear spin: δa gg /a gg ∼ δΦ ∼ 10 −9 .…”

Section: Nuclear-spin Independence Of the Scattering Lengthsmentioning

confidence: 99%

“…This can occur if the molecular 0 + g potential that correlates with the e-e atoms undergoes an avoided crossing with a potential curve that correlates with a lower energy pair of separated atoms (see, for example, Ref. [64]). Similar crossings that result in inelastic energy transfer collisions were examined for 1 P 1 + 1 S 0 collisions of alkaline earth atoms in Ref.…”

Section: Likelihood Of Lossy E-e Collisions and Possible Solutionsmentioning

confidence: 99%

See 2 more Smart Citations

Two-orbital S U(N) magnetism with ultracold alkaline-earth atoms

et al. 2010

View full text Add to dashboard Cite

Fermionic alkaline-earth atoms have unique properties that make them attractive candidates for the realization of novel atomic clocks and degenerate quantum gases. At the same time, they are attracting considerable theoretical attention in the context of quantum information processing. Here we demonstrate that when such atoms are loaded in optical lattices, they can be used as quantum simulators of unique many-body phenomena. In particular, we show that the decoupling of the nuclear spin from the electronic angular momentum can be used to implement many-body systems with an unprecedented degree of symmetry, characterized by the SU(N) group with N as large as 10. Moreover, the interplay of the nuclear spin with the electronic degree of freedom provided by a stable optically excited state allows for the study of spin-orbital physics. Such systems may provide valuable insights into strongly correlated physics of transition metal oxides, heavy fermion materials, and spin liquid phases.The interest in fermionic alkaline-earth atoms [1, 2, 3, 4, 5, 6, 7, 8] stems from their two key features: (1) the presence of a metastable excited state 3 P 0 coupled to the ground 1 S 0 state via an ultranarrow doubly-forbidden transition [1] and (2) the almost perfect decoupling [1] of the nuclear spin I from the electronic angular momentum J in these two states, since they both have J = 0. This decoupling implies that s-wave scattering lengths involving states 1 S 0 and 3 P 0 are independent of the nuclear spin, aside from the restrictions imposed by fermionic antisymmetry. We show that the resulting SU(N) spin symmetry (where N = 2I + 1 can be as large as 10) together with the possibility of combining (nuclear) spin physics with (electronic) orbital physics open up a wide field of extremely rich many-body systems with alkaline-earth atoms.In what follows, we derive the two-orbital SU(N)-symmetric Hubbard model describing alkaline-earth atoms in 1 S 0 and 3 P 0 states trapped in an optical lattice. We focus on specific parameter regimes characterized by full or partial atom localization due to strong atomic interactions, where simpler effective spin Hamiltonians can be derived. The interplay between orbital and spin degrees of freedom in such effective models is a central topic in quantum magnetism and has attracted tremendous interest in the condensed matter community. Alkaline earth atoms thus provide, on the one hand, a unique opportunity for the implementation of some of these models for the first time in a defect-free and fully controllable environment. On the other hand, they open a new arena to study a wide range of models, many of which have not been discussed previously, even theoretically. We demonstrate, in particular, how to implement the KugelKhomskii model studied in the context of transition metal oxides [9, 10,11,12,13], the Kondo lattice model [14,15,16,17,18,19,20,21,22,23,24,25,26] [27,28,29,30,31,32,33,34]. For example, we discuss how, by appropriately choosing the initial state, a single alkaline-earth atom s...

show abstract

Section: Nuclear-spin Independence Of the Scattering Lengthsmentioning

confidence: 69%

“…[63,64] 87 Sr. This yields the following estimate for the dependence of a gg on the nuclear spin: δa gg /a gg ∼ δΦ ∼ 10 −9 .…”

Section: Nuclear-spin Independence Of the Scattering Lengthsmentioning

confidence: 99%

Section: Likelihood Of Lossy E-e Collisions and Possible Solutionsmentioning

confidence: 99%

See 1 more Smart Citation

Two-orbital S U(N) magnetism with ultracold alkaline-earth atoms

et al. 2010

View full text Add to dashboard Cite

show abstract

“…Other potential energy curves do not show any unusual features, except for the broad maximum on the potential of the (4) 1 Σ + which is most likely due to the interaction with a still more excited state not reported in the present work. Except for the shallow double minima of the (2) Let us compare the pattern of the potential energy curves of the heteronuclear SrYb molecule with the homonuclear Sr 2 dimer 65 . In general, molecular orbitals constructed from the linear combinations of the Sr(5p)+Yb(6p) or Sr(4d)+Yb(5d) atomic orbitals are expected to have less bonding or antibonding character than the molecular orbitals constructed from the Sr(5p)+Sr(5p) or Sr(4d)+Sr(4d) atomic orbitals, because large atomic orbital energy differences make combination of these orbitals less effective.…”

Section: Electronic Structure Of Srybmentioning

confidence: 99%

Formation of ultracold SrYb molecules in an optical lattice by photoassociation spectroscopy: theoretical prospects

Tomza

Pawłowski

Jeziorska

et al. 2011

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

State-of-the-art ab initio techniques have been applied to compute the potential energy curves for the SrYb molecule in the Born-Oppenheimer approximation for the ground state and first fifteen excited singlet and triplet states. All the excited state potential energy curves were computed using the equation of motion approach within the coupled-cluster singles and doubles framework and large basis-sets, while the ground state potential was computed using the coupled cluster method with single, double, and noniterative triple excitations. The leading long-range coefficients describing the dispersion interactions at large interatomic distances are also reported. The electric transition dipole moments have been obtained as the first residue of the polarization propagator computed with the linear response coupled-cluster method restricted to single and double excitations. Spin-orbit coupling matrix elements have been evaluated using the multireference configuration interaction method restricted to single and double excitations with a large active space. The electronic structure data was employed to investigate the possibility of forming deeply bound ultracold SrYb molecules in an optical lattice in a photoassociation experiment using continuous-wave lasers. Photoassociation near the intercombination line transition of atomic strontium into the vibrational levels of the strongly spin-orbit mixed b 3 Σ + , a 3 Π, A 1 Π, and C 1 Π states with subsequent efficient stabilization into the v ′′ = 1 vibrational level of the electronic ground state is proposed. Ground state SrYb molecules can be accumulated by making use of collisional decay from v ′′ = 1 to v ′′ = 0. Alternatively, photoassociation and stabilization to v ′′ = 0 can proceed via stimulated Raman adiabatic passage provided that the trapping frequency of the optical lattice is large enough and phase coherence between the pulses can be maintained over at least tens of microseconds.

show abstract

“…Because only bound levels close to the potential dissociation limit are excited, v is independent of v and equal to twice the atomic linewidth at . By the same argument, DR can be approximated as independent of R [31] and is connected to the…”

Section: Prl 95 223002 (2005) P H Y S I C a L R E V I E W L E T T E R Smentioning

confidence: 99%

Spectroscopic Determination of thes-Wave Scattering Lengths ofSr86andSr

et al. 2005

View full text Add to dashboard Cite

We report the use of photoassociative spectroscopy to determine the ground-state s-wave scattering lengths for the main bosonic isotopes of strontium, 86 Sr and 88 Sr. Photoassociative transitions are driven with a laser red detuned by up to 1400 GHz from the 1 S 0 -1 P 1 atomic resonance at 461 nm. A minimum in the transition amplitude for 86 Sr at ÿ494 5 GHz allows us to determine the scattering lengths 610a 0 < a 86 < 2300a 0 for 86 Sr and a much smaller value of ÿ1a 0 < a 88 < 13a 0 for 88 Sr. DOI: 10.1103/PhysRevLett.95.223002 PACS numbers: 32.80.Pj Photoassociative spectroscopy (PAS) of ultracold gases, in which a laser field resonantly excites colliding atoms to rovibrational states of excited molecular potentials, is a powerful probe of atomic cold collisions [1]. Transition frequencies have been used to obtain dispersion coefficients of molecular potentials, which yield the most accurate value of the atomic excited-state lifetime [2 -5]. Transition amplitudes are related to the wave function for colliding ground-state atoms [6,7] and can be used to determine the ground-state s-wave scattering length [8][9][10][11][12][13].The s-wave scattering length is a crucial parameter for determining the efficiency of evaporative cooling and the stability of a Bose-Einstein condensate (BEC). It also sets the scale for collisional frequency shifts, which can limit the accuracy and stability of atomic frequency standards.The cold collision properties of alkaline-earth atoms such as strontium, calcium, and magnesium, and atoms with similar electronic structure, such as ytterbium, are currently the focus of intense study. These atoms possess narrow optical resonances that have great potential for optical frequency standards [14 -18]. Laser cooling on narrow transitions [19] is an efficient route to high phasespace density [20,21], and a BEC was recently produced with ytterbium [22]. Fundamental interest in alkaline-earth atoms is also high because their simple molecular potentials allow accurate tests of cold collision theory [23][24][25].PAS of calcium [12] and ytterbium [13] was recently used to determine s-wave scattering lengths of these atoms. This Letter reports the use of PAS to determine the groundstate s-wave scattering lengths for the main bosonic isotopes of strontium, 86 Sr and 88 Sr, which have relative abundances of 10% and 83%, respectively. We find a huge scattering length for 86 Sr of 610a 0 < a 86 < 2300a 0 . Appreciable uncertainty comes from the value of C 6 for the ground-state potential. In contrast, for 88 Sr we find ÿ1a 0 < a 88 < 13a 0 . Recently posted [5] PAS results for 88 Sr yielded an improved measurement of the 5s5p 1 P 1 atomic lifetime ( 5:263 0:004 ns), which we use in our analysis. Disagreement between our reported value of a 88 and results of Ref.[5] will be discussed below.For PAS of strontium, atoms are initially trapped in a magneto-optical trap (MOT) operating on the 461 nm 1 S 0 -1 P 1 transition, as described in Refs. [4,26]. We are able to produce pure samples of each iso...

show abstract

Valence ab initio calculation of the potential energy curves for the Sr2 dimer

Cited by 41 publications

References 25 publications

Two-orbital S U(N) magnetism with ultracold alkaline-earth atoms

Two-orbital S U(N) magnetism with ultracold alkaline-earth atoms

Formation of ultracold SrYb molecules in an optical lattice by photoassociation spectroscopy: theoretical prospects

Spectroscopic Determination of thes-Wave Scattering Lengths ofSr86andSr

Contact Info

Product

Resources

About