Controlled photoionization loading of 88Sr+ for precision ion-trap experiments

We report on a photoionization scheme for controlled loading of 88Sr+ ions into a radio-frequency (rf) ion trap. The two-step doubly-resonant process drives the 88Sr atom on the 5s21S0 – 5s5p1P1 transition at 461 nm using a frequency-doubled diode laser, and then excites the atom to the autoionizing (4d2+5p2) 1D2 state with 405 nm light from a free-running diode laser. This method of trap loading is quantitatively compared to electron bombardment loading, and shown to reduce the Sr vapour pressure required to load by four orders of magnitude. It also provides more than an order of magnitude reduction in the day-to-day variation of the voltages required to compensate micromotion. We additionally introduce a two-step atomic source consisting of an oven and hotplate, which reduces the number of impurities evaporated towards the trap. This is shown to significantly reduce fluctuations in required micromotion compensation voltages. The demonstrated reduction in flux and increased source purity are expected to improve the reliability of trap operation for precision ion-trap experiments.

[1]  B. Cannon,et al.  Diode laser based resonance ionization mass spectrometric measurement of strontium-90 , 1997 .

[2]  C. Monroe,et al.  Experimental Issues in Coherent Quantum-State Manipulation of Trapped Atomic Ions , 1997, Journal of research of the National Institute of Standards and Technology.

[3]  Patrick Gill,et al.  Improved three-dimensional control of a single strontium ion in an endcap trap , 2001 .

[4]  J. Chiaverini,et al.  Photoionization of strontium for trapped-ion quantum information processing , 2006 .

[5]  F. Schmidt-Kaler,et al.  Implementation of the Deutsch–Jozsa algorithm on an ion-trap quantum computer , 2003, Nature.

[6]  P. C. Haljan,et al.  Entanglement of trapped-ion clock states , 2005 .

[7]  F. Schmidt-Kaler,et al.  Realization of the Cirac–Zoller controlled-NOT quantum gate , 2003, Nature.

[8]  O. Gühne,et al.  03 21 7 2 3 M ar 2 00 6 Scalable multi-particle entanglement of trapped ions , 2006 .

[9]  Herbert Walther,et al.  Novel miniature ion traps , 1993 .

[10]  Jun Ye,et al.  Cooling and trapping of atomic strontium , 2003 .

[11]  D. Leibfried,et al.  Experimental demonstration of a robust, high-fidelity geometric two ion-qubit phase gate , 2003, Nature.

[12]  P. C. Haljan,et al.  Erratum: Zero-point cooling and low heating of trapped {sup 111}Cd{sup +} ions [Phys. Rev. A 70, 043408 (2004)] , 2006 .

[13]  R. B. Blakestad,et al.  Creation of a six-atom ‘Schrödinger cat’ state , 2005, Nature.

[14]  P. C. Haljan,et al.  Implementation of Grover's quantum search algorithm in a scalable system , 2005 .

[15]  A. M. Thommesen,et al.  Isotope selective loading of an ion trap using resonance-enhanced two-photon ionization , 2000 .

[16]  F. Schmidt-Kaler,et al.  Deterministic quantum teleportation with atoms , 2004, Nature.

[17]  Jr.,et al.  Efficient photoionization loading of trapped ions with ultrafast pulses , 2006, quant-ph/0608043.

[18]  Christian Kurtsiefer,et al.  Experimental study of anomalous heating and trap instabilities in a microscopic 137 Ba ion trap , 2002 .

[19]  Boris B. Blinov,et al.  Zero-point cooling and low heating of trapped {sup 111}Cd{sup +} ions , 2004, quant-ph/0404142.

[20]  M. A. Rowe,et al.  Heating of trapped ions from the quantum ground state , 2000 .

[21]  D. Leibfried,et al.  Toward Heisenberg-Limited Spectroscopy with Multiparticle Entangled States , 2004, Science.

[22]  M. Aymar,et al.  R-matrix calculation of eigenchannel multichannel quantum defect parameters for strontium , 1987 .

[23]  David J. Wineland,et al.  Minimization of ion micromotion in a Paul trap , 1998 .

[24]  A. Sinclair,et al.  Zero-point cooling and heating-rate measurements of a single Sr+88 ion , 2007 .

[25]  K. Bartschat,et al.  Near-threshold photoionization from the Sr I (5s5p) 1Po1 state , 1995 .

[26]  E. Riis,et al.  Optical Ramsey spectroscopy of a single trapped 88Sr+ ion , 2004 .

[27]  C. F. Roos,et al.  ‘Designer atoms’ for quantum metrology , 2006, Nature.

[28]  E. Knill,et al.  Deterministic quantum teleportation of atomic qubits , 2004, Nature.

[29]  J. P. Home,et al.  Isotope-selective photoionization for calcium ion trapping , 2004 .

[30]  F. Schmidt-Kaler,et al.  Simple and efficient photo-ionization loading of ions for precision ion-trapping experiments , 2001 .

[31]  A A Madej,et al.  Single, trapped Sr+ atom: laser cooling and quantum jumps by means of the 4d2D5/2-5s2S1/2 transition. , 1990, Optics letters.

[32]  C Langer,et al.  Spectroscopy Using Quantum Logic , 2005, Science.