Multipole Traps Martina Knoop

Transcription

1 Multipole Traps Martina Knoop CNRS/ Aix-Marseille Université, Marseille, France 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 1 1

2 Outline 1. Operation of multipole traps 2. Applications 3. Experimental issues 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 2 2

3 About multipole traps A clock for the Deep Space Network JPL, Pasadena/CA Challenges and opportunities Very large ion clouds Reduced Doppler shift Shuttling between the zones 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 3 3

4 2k-pole traps radial part axial part k=2 : quadrupole k=4 : octupole 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 4 4

5 2k-pole traps stability of the trajectories governed by Mathieu s equations Mathieu parameter non-linear dynamics. no more exact stability criteria and sensibility to initial conditions adiabaticity parameter, empirically limited to. 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 5 5

6 Motion in a multipole In the radial potential MolecularDynamics to accompanythe evolutionof structures Monte-Carlo methodsfor crystal structures 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 6 6

7 Non-neutral neutral plasma (cold charged fluid) DHE Dubin and TM O Neil, Rev Mod Phys (1999) T=10 000K Quadrupole T=300K Multipole T=5K C. Champenois, About the dynamics and thermodynamics of 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 7 trapped ions, J. Phys. B: At. Mol. Opt. Phys (2009) 7

8 Non-neutral neutral plasma (cold charged fluid) DHE Dubin and TM O Neil, Rev Mod Phys (1999) T=10 000K Quadrupole T=300K Multipole T=5K C. Champenois, About the dynamics and thermodynamics of 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 8 trapped ions, J. Phys. B: At. Mol. Opt. Phys (2009) 8

9 2k-pole trap Higher order flatter and more shallow 22 pole trap D Gerlich, Uni Chemnitz, Germany Adv Chem Phys LXXXII, 1 (1992) 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 9 9

10 2k-pole trap Higher order flatter and more shallow 22 pole trap D Gerlich, Uni Chemnitz, Germany Adv Chem Phys LXXXII, 1 (1992) 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 10 10

11 2k-poles Less rfheating Creation of different (crystal) structures : tubes, rings Symmetric structures (2D)?? Trapping range, initial conditions Laser power Detection efficiency 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 11 11

12 Outline 1. Operation of multipole traps 2. Applications 3. Experimental issues 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 12 12

13 Numerical simulations Molecular dynamics taking into account all forces (incllaser cooling as a real quantum process) Any potential 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 13 13

14 Some examples Transition from2 to 1 ion ring(s) Sympatheticcooling Modified multipole potentials How to makean ion ring 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 14 14

15 Structural phase transition Large ion numbers, concentric shells 100 ions 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 15 15

16 Structural phase transition From 2 rings to 1 M Marciante et al., ApplPhysB(2012) Distance ~2 µm 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 16 16

17 Structural phase transition 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 17 17

18 Structural phase transition 2 rings 1 ring 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 18 18

19 Structural phase transition For the double-ring structure, temperatures show an important dissymmetry. The temperature associated to tangent motions seems to be coupled to the axial one. The frequency for which the decoupling happens remains unexplained. (Is there a limit thickness of the single-ring?) 2 rings 1 ring 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 19 19

20 Sympathetic cooling Axial view 10 Calcium ions (m Ca = 40 uma) under laser-cooling sympathetically cooling 40 ions of mass m = 306 uma Program development: massively parallel computation. (O-MPI, CUDA ) 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 20 20

21 Modifying the multipole potential Pseudopotential of a 2k-pole trap: time-average where is the rf-electric field. To each node of the rf-field corresponds a minimum of the pseudopotential. Nodes can be created by superposition of different rf-electric fields. i.e. in a linear quadrupoletrap : a single central line 28 July 2013 Martina Knoop IV Strings of ions in linear multipole traps Enrico Fermi School/course 189 Varenna, IT 21 21

22 Modifying the multipole potential Total radial component of the rf-electric field: Parallel ion strings in multipole traps 1-1 Tunable! 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 22 22

23 Modifying the multipole potential Pseudo-potential: Need for a static compensation: 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 23 23

24 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 24 24

25 Higher orders and so on M. Marciante et al., PRA 83, (R) (2011) 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 25 25

26 Creation of ion rings Laser-cooled ion cloud of a few ions in a multipolepotential 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 26 26

27 Ion ring(s) ) in a multipole An ion ring for frequency metrology (increasing the number of ions from 1 to N) 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 27 27

28 Precision spectroscopy for ion rings What for? Perfectly symmetric ion chain (compared to linear) Quantum information, metrology, Interaction of two rings : Test bed for Kibble-Zurek mechanism (defect during NE phase transition) Dynamics of kinks Discrete solitons Introduction of asymmetries/impurities Variation of distance 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 28 28

29 Outline 1. Operation of multipole traps 2. Applications 3. Experimental issues 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 29 29

30 State of the art In a hexapole trap K Okada, Sophia University, Tokyo 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 30 30

31 Motivation Very large ion crystals Long range interactions Structural transitions Ion dynamics Multipole (k=4) Quadrupole 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 31 31

32 Ions in a double trap 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 32 32

33 Experimental set-up Double trap 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 33 33

34 Experimental set-up Laser 389 nm 423 nm 397 nm 866 nm 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 34 34

35 Ion Creation ~ 7x10 5 Ca+ ions ~ 3x10 5 Ca+ ions 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 35 35

36 UDC= 2000V 100V 200V 400V 600V 913V 50V 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 36 36

37 Shuttling an ion cloud 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 37 37

38 Shuttling ions Double trap along a common z-axis No heating No ion loss Many cycles macroscopic TRANSPORT Fidelity 100 % 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 38 38

39 Shuttling ions Double trap along a common z-axis No heating No ion loss Many cycles macroscopic TRANSPORT Fidelity 100 % 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 39 39

40 Shuttling ions -simulations Ideal transport described by a gate function Analytical energy gain for zero initial energy Different techniques developed for transport of single ions in quantum information Reichle et al., Fortschritte der Physik 54, 666 (2006) Hucul et al., Quant. Inf. Comp. 8, (2008) Huber et al., New Journal of Physics 10, (2008) 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 40 40

41 Transport Simulations using SIMION and Fortran July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 41 41

42 Transport time Simulations using SIMION and Fortran July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 42 42

43 Heating introduced by transport linear gate sinusoidal gate hyperbolic gate 1 ion 1000 ions 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 43 43

44 Transport between two quads Shuttling back and forth Ion number? 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 44 44

45 Transport between two quads Shuttling back and forth Ion number? 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 45 45

46 Transport 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 46 46

47 Aspect ratio fittedaspect ratio calculated aspect ratio 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 47 47

48 Transport Influence of UDC 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 48 48

49 Transport 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 49 49

50 Outlook Optimal control transport (similar to D Guéry-Odelin) No heating, no loss Simand exp Crystallization in the multipole Trap 10 7 ions (explore crystal structures) 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 50 50

51 Credit PIIM Mathieu Marciante (now in Lyon) Caroline Champenois Didier Guyomarc h Gaëtan Hagel, Marie Houssin Marius Kamsap Olivier Morizot, Jofre Pedregosa MK Agence Nationale de la Recherche, CNES, Region Provence Alpes Côte d Azur 28 July 2013 Martina Knoop Enrico Fermi School/course 189 Varenna, IT 51 51