JQI seminar July 8, 2010 ATOMIC ATOMIC CALCULATIONS: CALCULATIONS: RECENT RECENT ADVANCES ADVANCES AND AND MODERN MODERN APPLICATIONS APPLICATIONS MARIANNA SAFRONOVA OUTLINE OUTLINE • Selected applications of atomic calculations • Study of fundamental symmetries • Atomic clocks • Optical cooling and trapping and quantum information • Examples: magic wavelengths • Present status of theory • How accurate are theory values? • Present challenges • Development of CI+all-order method for group II atoms • Future prospects ATOMIC ATOMIC CALCULATIONS CALCULATIONS FOR FOR STUDY STUDY OF OF FUNDAMENTAL FUNDAMENTAL SYMMETRIES SYMMETRIES TRANSFORMATIONS TRANSFORMATIONS AND AND SYMMETRIES SYMMETRIES Translation Momentum conservation Translation in time Energy conservation Rotation Conservation of angular momentum [C] Charge conjugation C-invariance [P] Spatial inversion Parity conservation (P-invariance) [T] Time reversal T-invariance [CP] [CPT] r→ ─r Parity Parity Violation Violation Parity-transformed world: Turn the mirror image upside down. The parity-transformed world is not identical with the real world. Parity is not conserved. PARITY PARITY VIOLATION VIOLATION IN IN ATOMS ATOMS NUCLEAR SPINSPIN-INDEPENDENT PNC: SEARCHES FOR NEW PHYSICS BEYOND THE STANDARD MODEL e q e Z0 q Weak Charge QW W NUCLEAR SPINSPIN-DEPENDENT PNC: STUDY OF PNC IN THE NUCLEUS a Nuclear anapole moment STANDARD STANDARD MODEL MODEL Searches Searches for for New New Physics Physics Beyond Beyond the the Standard Standard Model Model High energies (1) Search for new processes or particles directly (2) Study (very precisely!) quantities which Standard Model predicts and compare the result with its prediction Weak charge QW Low energies http://public.web.cern.ch/, Cs experiment, University of Colorado THE THE MOST MOST PRECISE PRECISE MEASUREMENT MEASUREMENT OF OF PNC PNC AMPLITUDE AMPLITUDE (IN (IN CESIUM) CESIUM) C.S. Wood et al. Science 275, 1759 (1997) F=4 7s F=3 1 6s 2 F=4 F=3 0.3% accuracy Im ( EPNC ) β −1.6349(80) mV cm = −1.5576(77) mV cm Stark interference scheme to measure ratio of the PNC amplitude and the Stark-induced amplitude β 1 2 PARITY PARITY VIOLATION VIOLATION IN IN ATOMS ATOMS NUCLEAR SPINSPIN-INDEPENDENT PNC: SEARCHES FOR NEW PHYSICS BEYOND THE STANDARD MODEL Present status: agreement with the Standard Model NUCLEAR SPINSPIN-DEPENDENT PNC: STUDY OF PNC IN THE NUCLEUS a Nuclear anapole moment SPINSPIN SPINDEPENDENT PARITY PARITY VIOLATION: VIOLATION: SPIN--DEPENDENT NUCLEAR NUCLEAR ANAPOLE ANAPOLE MOMENT MOMENT a Parity-violating nuclear moment F=4 7s F=3 1 6s 2 H (a) PNC = GF 2 κ a α ⋅ I ρv (r ) F=4 F=3 Valence nucleon density Anapole moment Nuclear anapole moment is parity-odd, time-reversal-even E1 moment of the electromagnetic current operator. CONSTRAINTS CONSTRAINTS ON ON NUCLEAR NUCLEAR WEAK WEAK COUPLING COUPLING CONTANTS CONTANTS W. C. Haxton and C. E. Wieman, Ann. Rev. Nucl. Part. Sci. 51, 261 (2001) NUCLEAR NUCLEAR ANAPOLE ANAPOLE MOMENT: MOMENT: TEST TEST OF OF HADRONIC HADRONIC WEAK WEAK INTERATIONS INTERATIONS The constraints obtained from the Cs experiment were found to be inconsistent with constraints from other nuclear PNC measurements, which favor a smaller value of the133Cs anapole moment. All-order (LCCSD) calculation of spin-dependent PNC amplitude: k = 0.107(16)* [ 1% theory accuracy ] No significant difference with previous value k = 0.112(16) is found. NEED NEW EXPERIMENTS!!! Fr, Yb, Ra+ *M.S. Safronova, Rupsi Pal, Dansha Jiang, M.G. Kozlov, W.R. Johnson, and U.I. Safronova, Nuclear Physics A 827 (2009) 411c WHY WHY DO DO WE WE NEED NEED ATOMIC ATOMIC CALCULATIONS CALCULATIONS TO TO STUDY STUDY PARITY PARITY VIOLATION? VIOLATION? (1)Present experiments can not be analyzed without theoretical value of PNC amplitude in terms of Qw. (2)Theoretical calculation of spin-dependent PNC amplitude is needed to determine anapole moment from experiment. (3) Other parity conserving quantities are needed. Note: need to know theoretical uncertainties! TRANSFORMATIONS TRANSFORMATIONS AND AND SYMMETRIES SYMMETRIES Translation Momentum conservation Translation in time Energy conservation Rotation Conservation of angular momentum [C] Charge conjugation C-invariance [P] Spatial inversion Parity conservation (P-invariance) [T] Time reversal T-invariance [CP] [CPT] PERMANENT ELECTRIC PERMANENT ELECTRICELECTRICDIPOLE ELECTRIC--DIPOLE MOMENT MOMENT (( EDM EDM )) Time-reversal invariance must be violated for an elementary particle or atom to possess a permanent EDM. S d t → −t S → −S d→d d S d=d S d =0 S EDM EDM AND AND NEW NEW PHYSICS PHYSICS Many theories beyond the Standard Model predict EDM within or just beyond the present experimental capabilities. Yale I Yale II (projected) (projected) Berkeley (2002) David DeMille, Yale PANIC 2005 MultiHiggs Extended Technicolor Left-Right Symmetric Lepton FlavorChanging Standard Model Alignment Split SUSY SO(10) GUT Seesaw Neutrino Yukawa Couplings Accidental Cancellations -25 10 -26 Exact Universality Approx. Universality Heavy sFermions Naïve SUSY 10 Approx. CP 10 -27 10 -28 10 -29 10 -30 10 -31 10 de (e⋅cm) -32 10 -33 10 -34 ~ 10 -39 10 -40 ATOMIC ATOMIC CALCULATIONS CALCULATIONS AND AND SEARCH SEARCH FOR FOR EDM EDM EDM effects are enhanced in some heavy atoms and molecules. Theory is needed to calculate enhancement factors and search for new systems for EDM detection. Recent new limit on the EDM of 199Hg | d(199Hg) | < 3.1 x 10-29 e cm Phys. Rev. Lett. 102, 101601 (2009) ATOMIC ATOMIC CLOCKS CLOCKS Microwave Transitions Optical Transitions Blackbody Radiation Shifts and Theoretical Contributions to Atomic Clock Research, M. S. Safronova, Dansha Jiang, Bindiya Arora, Charles W. Clark, M. G. Kozlov, U. I. Safronova, and W. R. Johnson, Special Issue of IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control 57, 94 (2010). ATOMIC ATOMIC CALCULATIONS CALCULATIONS & & MORE MORE PRECISE PRECISE CLOCKS CLOCKS (1)Prediction of atomic properties required for new clock proposals New clock proposals require both estimation of the atomic properties for details of the proposals (transition rates, lifetimes, branching rations, magic wavelength, scattering rates, etc.) and evaluation of the systematic shifts (Zeeman shift, electric quadruple shift, blackbody radiation shift, ac Stark shifts due to various lasers fields, etc.). (2)Determination of the quantities contributing to the uncertainty budget of the existing schemes. In the case of the well-developed proposals, one of the main current uncertainty issues is the blackbody radiation shift. BLACKBODY BLACKBODY RADIATION RADIATION SHIFT SHIFT LEVEL B CLOCK TRANSITION LEVEL A T=0K T = 300 K ∆BBR Transition frequency should be corrected to account for the effect of the black body radiation at T=300K. BBR BBR SHIFT SHIFT AND AND POLARIZABILITY POLARIZABILITY BBR shift of atomic level can be expressed in terms of a scalar static polarizability to a good approximation [1]: 4 ∆ν BBR 1 2 T (K ) = − α 0 (0)(831.9V / m) (1+η ) 2 300 Dynamic Dynamic correction correction Dynamic correction is generally small. Multipolar corrections (M1 and E2) are suppressed by α2 [1]. VECTOR & TENSOR POLARIZABILITY AVERAGE OUT DUE TO THE ISOTROPIC NATURE OF FIELD. [1] Sergey Porsev and Andrei Derevianko, Physical Review A 74, 020502R (2006) MICROWAVE MICROWAVE TRANSITIONS TRANSITIONS OPTICAL OPTICAL TRANSITIONS TRANSITIONS Sr+ Cs 6s F=4 4d5/2 5s1/2 6s F=3 In lowest (second) order the polarizabilities of ground hyperfine 6s1/2 F=4 and F=3 states are the same. (1) (1) DDT , DT D, T D 2 2 n Dv 1 α = ∑ 3(2 jv + 1) n En − Ev 0 v Therefore, the third-order F-dependent polarizability αF (0) has to be calculated. (1) Lowest-order polarizability terms D2 term BLACKBODY BLACKBODY RADIATION RADIATION SHIFTS SHIFTS IN IN OPTICAL OPTICAL FREQUENCY FREQUENCY STANDARDS: STANDARDS: (1) (1) MONOVALENT MONOVALENT SYSTEMS SYSTEMS (2) (2) DIVALENT DIVALENT SYSTEMS SYSTEMS (3) (3) OTHER, OTHER, MORE MORE COMPLICATED COMPLICATED SYSTEMS SYSTEMS + Ca (4s1/2 →3d5/2 ) Sr+ (5s1/2 → 4d5/2 ) Ba+ (6s1/2 →5d5/2 ) Ra+ (7s1/2 → 6d5/2 ) Mg, Ca, Zn, Cd, Sr, Al+, In+, Yb, Hg ( ns2 1S0 – nsnp 3P) Hg+ (5d 106s – 5d 96s2) Yb+ (4f 146s – 4f 136s2) ++ EXAMPLE: BBR SHIFT IN Sr S EXAMPLE: BBR SHIFT IN Sr S Present α0(5s1/2) 91.3(9) Need precise lifetime measurements α0(4d5/2) 62.0(5) nf tail contribution issue has been resolved Present ∆(5s1/2 → 4d5/2) 0.250(9) Ref.[1] 0.33(12) Ref. [2] 0.33(9) [1] A. A. Madej et al., PRA 70, 012507 (2004); [2] H. S. Margolis et al., Science 306, 19 (2004). 1% Dynamic correction, E2 and M1 corrections negligible Sr+: Ca+: Dansha Jiang, Bindiya Arora, M. S. Safronova, and Charles W. Clark, J. Phys. B 42 154020 (2010). Bindiya Arora, M.S. Safronova, and Charles W. Clark, Phys. Rev. A 76, 064501 (2007) Summary of the fractional uncertainties δν/ν0 due to BBR shift and the fractional error in the absolute transition frequency induced by the BBR shift uncertainty at T = 300 K in various frequency standards. Present M. S. Safronova et al., IEEE - TUFFC 57, 94 (2010). 5×10-17 ATOMS ATOMS IN IN OPTICAL OPTICAL LATTICES LATTICES • Cancellations of ac Start shifts: state-insensitive optical cooling and trapping • State-insensitive bichromatic optical trapping schemes • Simultaneous optical trapping of two different alkali-metal species • Determinations of wavelength where atoms will not be trapped • Calculations of relevant atomic properties: dipole matrix elements, atomic polarizabilities, magic wavelengths, scattering rates, lifetimes, etc. Optimizing the fast Rydberg quantum gate, M.S. Safronova, C. J. Williams, and C. W. Clark, Phys. Rev. A 67, 040303 (2003) . Frequency-dependent polarizabilities of alkali atoms from ultraviolet through infrared spectral regions, M.S. Safronova, Bindiya Arora, and Charles W. Clark, Phys. Rev. A 73, 022505 (2006) Magic wavelengths for the ns-np transitions in alkali-metal atoms, Bindiya Arora, M.S. Safronova, and C. W. Clark, Phys. Rev. A 76, 052509 (2007). Theory and applications of atomic and ionic polarizabilities (review paper), J. Mitroy, M.S. Safronova, and Charles W. Clark, submitted to J. Phys. B (2010) State-insensitive bichromatic optical trapping, Bindiya Arora, M.S. Safronova, and C. W. Clark, submitted to Phys. Rev. A (2010) MAGIC MAGIC WAVELENGTH WAVELENGTH Atom in state B sees potential UB Atom in state A sees potential UA Magic wavelength λmagic magic is the wavelength for which the optical potential U experienced by an atom is independent on its state U ∝ α (λ ) LOCATING LOCATING MAGIC MAGIC WAVELENGTH WAVELENGTH α (λ) S State P State wavelength λ m a g ic POLARIZABILITY POLARIZABILITY OF OF AN AN ALKALI ALKALI ATOM ATOM IN IN A A STATE STATE vv α = α c + α vc + α v Core term Valence term (dominant) Compensation term Example: Scalar dipole polarizability Electric-dipole reduced matrix element ( En − Ev ) n D v 1 αv ( ω ) = ∑ 3(2 jv + 1) n ( En − Ev ) 2 − ω 2 2 RELATIVISTIC ALL RELATIVISTIC ALLALLORDER METHOD METHOD ALL--ORDER Sum over infinite sets of many-body perturbation theory (MBPT) terms. Calculate the atomic wave functions and energies Scheme: Calculate various matrix elements H Ψv = E Ψv Calculate “derived” properties useful for particular problems RESULTS ALKALI RESULTS FOR FOR ALKALIALKALIMETAL ATOMS: ATOMS: ALKALI--METAL E1 E1 TRANSITION TRANSITION MATRIX MATRIX ELEMENTS ELEMENTS IN IN Na 3p1/2-3s K 4p1/2-4s Rb 5p1/2-5s Cs Fr 6p1/2-6s 7p1/2-7s All-order 3.531 4.098 4.221 4.478 4.256 Experiment 3.5246(23) 4.102(5) 4.231(3) 4.489(6) 4.277(8) Difference 0.18% 0.1% 0.24% 0.24% 0.5% Experiment Na,K,Rb: U. Volz and H. Schmoranzer, Phys. Scr. T65, 48 (1996), Theory Cs: R.J. Rafac et al., Phys. Rev. A 60, 3648 (1999), Fr: J.E. Simsarian et al., Phys. Rev. A 57, 2448 (1998) M.S. Safronova, W.R. Johnson, and A. Derevianko, Phys. Rev. A 60, 4476 (1999) Example: “Best set” Rb matrix elements Magic wavelengths for the 5p3/2 - 5s transition of Rb.. ac Stark shifts for the transition from 5p3/2F′=3 =3 M′ M sublevels to 5s FM sublevels in Rb. The electric field intensity is taken to be 1 MW/cm2. MAGIC MAGIC WAVELENGTH WAVELENGTH FOR FOR CS CS α v = α 0 + α 2 MJ = ±3/2 α v = α 0 − α 2 MJ = ±1/2 10000 6S1/2 6P3/2 α (a.u.) 8000 6000 932 nm α0+ α2 4000 2000 0 925 λmagic Other* Other* 938 nm λmagic around 935nm α0- α2 930 935 940 λ (nm) 945 950 955 * Kimble et al. PRL 90(13), 133602(2003) BICHROMATIC BICHROMATIC OPTICAL OPTICAL TRAPPING TRAPPING atom Trap laser Control laser A combination of trapping and control lasers is used to minimize the variance of the potential experienced by the atom in ground and excited states. Surface plot for the 5s and 5p3/2 |m| = 1/2 state polarizabilities as a function of laser wavelengths λ1 and λ2 for equal intensities of both lasers. Magic wavelengths for the the 5s and 5p3/2 | m| = 1/2 states for λ1 =800-810nm and λ2=2 λ1 for various intensities of both lasers. The intensity ratio (ε1/ε2)2 ranges from 1 to 2. OTHER OTHER APPLICATIONS APPLICATIONS • Variation of fundamental constants • Long-range interaction coefficients • Data for astrophysics • Actinide ion studies for chemistry models • Benchmark tests of theory and experiment • Cross-checks of various experiments • Determination of nuclear magnetic moment in Fr • Calculation of isotope shifts •… MONOVALENT MONOVALENT SYSTEMS: SYSTEMS: VERY VERY BRIEF BRIEF SUMMARY SUMMARY OF OF WHAT WHAT WE WE CALCULATED ALL CALCULATED WITH WITH ALLALLORDER METHOD METHOD ALL--ORDER Properties Systems • Energies • Transition matrix elements (E1, E2, E3, M1) Li, Na, Mg II, Al III, • Static and dynamic polarizabilities & applications Si IV, P V, S VI, K, Dipole (scalar and tensor) Ca II, In, In-like ions, Quadrupole, Octupole Ga, Ga-like ions, Rb, Light shifts Cs, Ba II, Tl, Fr, Th IV, Black-body radiation shifts U V, other Fr-like ions, Magic wavelengths Ra II • Hyperfine constants • C3 and C6 coefficients • Parity-nonconserving amplitudes (derived weak charge and anapole moment) • Isotope shifts (field shift and one-body part of specific mass shift) • Atomic quadrupole moments • Nuclear magnetic moment (Fr), from hyperfine data http://www.physics.udel.edu/~msafrono HOW HOW TO TO EVALUATE EVALUATE UNCERTAINTY UNCERTAINTY OF OF THEORETICAL THEORETICAL CALCULATIONS? CALCULATIONS? THEORY: THEORY: EVALUATION EVALUATION OF OF THE THE UNCERTAINTY UNCERTAINTY HOW TO ESTIMATE WHAT YOU DO NOT KNOW? I. Ab initio calculations in different approximations: (a) Evaluation of the size of the correlation corrections (b) Importance of the high-order contributions (c) Distribution of the correlation correction II. Semi-empirical scaling: estimate missing terms EXAMPLE: EXAMPLE: QUADRUPOLE QUADRUPOLE MOMENT MOMENT OF OF ++ 3D STATE IN Ca C 3D5/2 C 5/2 STATE IN Ca Electric quadrupole moments of metastable states of Ca+, Sr+, and Ba+, Dansha Jiang and Bindiya Arora and M. S. Safronova, Phys. Rev. A 78, 022514 (2008) ++ 3D QUADRUPOLE MOMENT IN CA 3D5/2 5/2 QUADRUPOLE MOMENT IN CA Lowest order 2.451 Third order 1.610 All order (SD) 1.785 All order (SDpT) 1.837 Coupled-cluster SD (CCSD) 1.822 Estimate omitted corrections Final quadrupole moment Final results: results: 3d 3d5/2 quadrupole moment 5/2 Lowest order 2.454 Third order 1.849 1.849 (13) (13) 1.610 All order (SD), scaled All-order (CCSD), scaled All order (SDpT) All order (SDpT), scaled 1.849 1.851 1.837 1.836 Experiment Experiment 1.83(1) 1.83(1) Experiment: C. F. Roos, M. Chwalla, K. Kim, M. Riebe, and R. Blatt, Nature 443, 316 (2006). DEVELOPMENT OF HIGHHIGH-PRECISION METHODS PRESENT STATUS OF THEORY AND NEED FOR FURTHER DEVELOPMENT All-order Correlation potential CI+MBPT MOTIVATION: MOTIVATION: STUDY STUDY OF OF GROUP GROUP II II –– TYPE TYPE SYSTEMS SYSTEMS • • • • Mg Mg Ca Ca Sr Sr Ba Ba Ra Ra Atomic clocks Study of parity violation (Yb) Zn Zn Search for EDM (Ra) Cd Cd Degenerate quantum gases, Hg Hg alkali-group II mixtures Yb Yb • Quantum information • Variation of fundamental constants + + Divalent Divalent ions: ions:Al Al+,, In In+,, etc. etc. SUMMARY SUMMARY OF OF THEORY THEORY METHODS METHODS FOR FOR ATOMIC ATOMIC STRUCTURE STRUCTURE • Configuration interaction (CI) • Many-body perturbation theory • Relativistic all-order method (coupled-cluster) • Correlation - potential method • Configuration interaction + second-order MBPT • Configuration interaction + all-order method* *under development GOAL GOAL OF OF THE THE PRESENT PRESENT PROJECT: PROJECT: CALCULATE CALCULATE PROPERTIES PROPERTIES OF OF GROUP GROUP II II ATOMS ATOMS WITH WITH PRECISION PRECISION COMPARABLE COMPARABLE TO ALKALI TO ALKALIALKALIMETAL ATOMS ATOMS ALKALI--METAL CONFIGURATION CONFIGURATION INTERACTION INTERACTION METHOD METHOD Ψ = ∑ ci Φ i (H Single-electron valence basis states i eff − E)Ψ = 0 Example: two particle system: H eff = h1 (r1 ) + h1 (r2 ) + h2 (r1 , r2 ) one−body two−body part part 1 r1 − r2 CONFIGURATION CONFIGURATION INTERACTION INTERACTION ++ ALLALL ALLORDER METHOD METHOD ALL--ORDER CI works for systems with many valence electrons but can not accurately account for core-valence and core-core correlations. All-order (coupled-cluster) method can not accurately describe valence-valence correlation for large systems but accounts well for core-core and core-valence correlations. Therefore, two methods are combined to acquire benefits from both approaches. CONFIGURATION CONFIGURATION INTERACTION INTERACTION METHOD ALL METHOD ++ ALLALLORDER ALL--ORDER Heff is modified using all-order calculation h1 → h1 + Σ1 h2 → h2 + Σ 2 Σ1 , Σ 2 (H eff − E)Ψ = 0 are obtained using all-order method used for alkali-metal atoms with appropriate modification In the all-order method, dominant correlation corrections are summed to all orders of perturbation theory. CI ALL CI ++ ALLALLORDER RESULTS RESULTS ALL--ORDER Two-electron binding energies, differences with experiment Atom Mg Ca Zn Sr Cd Ba Hg Ra CI 1.9% 4.1% 8.0% 5.2% 9.6% 6.4% 11.8% 7.3% CI + MBPT 0.11% 0.7% 0.7% 1.0% 1.4% 1.9% 2.5% 2.3% CI + All-order 0.03% 0.3% 0.4 % 0.4% 0.2% 0.6% 0.5% 0.67% Development of a configuration-interaction plus all-order method for atomic calculations, M.S. Safronova, M. G. Kozlov, W.R. Johnson, Dansha Jiang, Phys. Rev. A 80, 012516 (2009). Cd,, Zn, Z , AND Sr POLARIZABILITIES, PRELIMINARY RESULTS (a.u.) Zn CI CI+MBPT CI + All-order 4s2 1S0 46.2 39.45 39.28 4s4p 3P0 77.9 69.18 67.97 CI CI+MBPT CI+All-order 5s2 1S0 59.2 45.82 46.55 5s5p 3P0 91.2 76.75 76.54 Cd Sr CI +MBPT CI+all-order Recomm.* 5s2 1S0 195.6 198.0 197.2(2) 5s5p 3P0 483.6 459.4 458.3(3.6) *From expt. matrix elements, S. G. Porsev and A. Derevianko, PRA 74, 020502R (2006). Cd,, Z Zn,, Sr, and Hg MAGIC WAVELENGTHS, PRELIMINARY RESULTS (nm) Sr Present 813.45 Cd Zn Present 423(4) 414(5) Hg Present 365(5) Expt. [1] 813.42735(40) Theory [2] 360 [1] A. D. Ludlow et al., Science 319, 1805 (2008) [2] H. Hachisu et al., Phys. Rev. Lett. 100, 053001 (2008) CONCLUSION CONCLUSION Parity Violation Atomic Clocks P1/2 Future: New Systems New Methods, New Problems D5/2 Qubit S1/2 Quantum information