Progress of Ytterbium Ion Optical Frequency Standard in India

Transcription

1 Progress of Ytterbium Ion Optical Frequency Standard in India Subhadeep De, Neha Batra, Atish Roy, Lakhi Sharma, Kritika Sharma, Subhasis Panja, and Vijay Narain Ojha CSIR-National Physical Laboratory, New Delhi, India ATF Workshop, APMP November 2017

2 : Yb-ion N. Huntemann et. al., Phys. Rev. Lett. 116, (2016) : Sr-atom I. Ushijima et. al., Nature Photonics 9, 185 (2015)

3 World wide Trapped Ion Optical Frequency Standards Ion λ [nm ] Transition Laboratories 223 Ra S 1/2 2 D 3/2 (E2) KVI Netherlands 199 Hg S 1/2 2 D 5/2 (E2) NIST USA 171 Yb Hg Lu S 0 3 D 1 (M2) NUS Singapore 171 Yb S 1/2 2 D 3/2 (E2) PTB Germany CSIR-NPL 171 Yb S 1/2 2 F 5/2 (E3) NPL UK, PTB Germany, N. Huntemann, et. al., PRL 108, (2012). 88 Sr + S. A. Diddams, et. al., Science 293, 825 (2001). 27 Al In S 0 3 P 0 (HIT) MPQ Germany, U. Washington, NICT Japan 88 Sr S 1/2 2 D 5/2 (E2) NPL UK, NRC Canada 167 nm 267 nm (HIT) Δν nat =0.5 mhz 43 Ca S 1/2 2 D 5/2 (E2) Uibk Innsbruck, CRL Japan, CAS China 27 Al S 0 3 P 0 (HIT) NIST USA, VU Netherlands H. S. Margolis, et. al., Science 306, 1355 (2004). T. Rosenband, et. al., PRL 98, (2007).

4 Probing Temporal Constancy of Fundamental Constants Fundamental Physics: s or better clock accuracy is required Is it really a constant? NO! Comparing Hg + & Al + transitions Ref. T. Rosenband,et. al., Science 319, 1808 (2009). year -1 Sensitivity Inter-comparison of Yb + with Sr optical clocks Sr-atom time Yb + Table is adapted from - H. S. Margolis, Contemporary phys. 51, 37 (2010).

5 Probing the Local Lorenz Invariance (LLI) violation with Yb-ion Master clock R. Bluhm, et. al., Phys. Rev. Lett. 88, (2002) On board clock ISS Estimated sensitivity of LLI-violation clock 2 clock 1 Table is adapted from V. A. Dzuba, et. al., Nature Phys. doi: /nphys3610 (2016). Energy level shift of the state: Local position invariance (LPI) Local Lorenz invariance (LLI)

6 repump 1 Single Trapped ion Optical- Standards Electrodynamic (Paul) Trap Energy levels of 171 Yb + 4f 13 5d6s 1 D[3/2] 3/ f 13 5d6s 3 D[3/2] 1/2 1 4f 14 6p 2 P 1/2 1 0 atom ion Continuum 4f 14 5d 2 D 3/ nm 760 nm (quadrupole ) nm 4 4f 14 6s6p 1 P nm 6s 2 4f 13 2 F 7/2 3 4f 14 6s 2 1 S nm 4f 14 6s 2 S 1/2 1 0

7 Hyperbolic Trap Ion Linear Trap Ion Ring Trap End-cap Trap Ion Inner electrode Outer electrode

8 Trap Geometry has influence Nature of the confining potential (desired is quadrupole) Trajectory of the ions (micromotions) Systematic uncertainty (Electric quadupole shift)

9 a40/a20 Identifying The Suitable Trap Geometry a60/a20 Anharmonicity Schrama (1993) Beaty (1986) Beaty (1986) Stein (2010) NPL India a 40 / a a 60 / a a 80 / a a 10 0 / a Inner Angle Inner Angle

10 Motion of ion in the potential z Trajectory z x x y y Micromotions - not curable by laser cooling Micromotion measurement in- D. J. Berkeland, et. al., J. App. Phys. 83, 5025 (1998). J. Keller, et. al., arxiv: v1 (2015).

11 2r o = 1 mm, θ i = 10 o, θ o = 45 o 2r o = 1 mm, θ i = 11 o, θ o = 45 o 2r o = 0.5 mm, θ i = 0 o, θ o = 45 o 2r o = 1 mm, 2z o = 0.6 mm, θ i 2z o θ o 2z o = 0.6 mm, θ i = 0 o, θ o = 45 o 2r o

12 1 2 3 Drawbacks: More degrees of rotations due to multiple fitting screws Mutual misalignment Tight fitting of the electrodes at desired precision failed always Bulky Macor insulator Blocking of the lights due to overall bulky structure Drawbacks: Relative misalignment resulting from single screw assembly Difficult assemble the electrodes by tight fitting Advantages: NO obstruction of lights coming at the desired angles NO relative rotation Easy electrode assembly TWO legs for mounting with the feedthrough gives better stability Mounting hole for Pt100

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15 Electric Quadrupole Shift Theory in W. M. Itano, J. Res. Nat. Inst. Stand. Tech., USA (2000). electric field gradient quadrupole moment Potential: Electric field: Electric field gradients: Method 5 D 3/2 [ea o2 ] Ref. 2 F 7/2 [ea o2 ] Ref. Theory W. M. tano, PRA 73, (2006) Theory K. V. P. Latha et. al., PRA 76, (2007) Theory 2.068(12) D. K. Nandy et. al., PRA 90, (2014) Theory 2.079(20) N. Batra et. al., Chin. Phys. B 25, (2016) Expt. 2.08(11) T. Schneider et. al., PRL 94, (2005) 2z o -Θ i -Θ o are 0.7 mm P. J. Blythe et. al., JPB 36, 981 (2003) S. G. Porsev et. al., PRA 86, (2012) (20) D. K. Nandy et. al., PRA 90, (2014) (21) N. Batra et. al., Chin. Phys. B 25, (2016) (5) N. Huntemann et. al., PRL 108, (2012) 2r o -Θ i -Θ o are 1 mm mm mm-0-45

16 Effect of the Loads Resulting from the Trap UHV Chamber Trap R 7 R 1 R 5 R 6 C5 C 6 C 3 R 4 C1 C 3 R2 R3 C4 R 4 C 8 C 7 C 9 R 7 R 1 R 6 C 5 C 6 C 2 R 5 R i and C i indicate resistances and capacitances: Estimated analytically and through numerical analysis (COMSOL Multiphysics)

17 Effect of the Loads Resulting from the Trap R 5 R 7 R 1 C 3 R 6 C 5 C 6 R 3 R 4 C 4 C 7 C 8 C 9 C 1 R 2 C 2 C 3 R 4 C 6 R 6 R 7 R 1 C 5 R 5

18 Effect of the Loads Resulting from the Trap Extra Micromotions Variation of resonance frequency and quality factor

19 Present Status of the Experiment Designing the precision ion trap Creation of the lab for the optical clock experiment UHV chamber for trapping ions Lasers Photoionization : 399 nm Laser cooling : nm 935 nm 760 nm Clock : 467 nm Availability Not yet Helical resonator for rf delivery to the trap Ytterbium oven Laser systems

20 Contd. - Present Status of the Experiment Electronic subsystems Automation of the experiment Optics for Imaging single ion is in process

21 STIOS lab November 2017

22 Progress of the Optical Clock project at CSIR-NPL Ion trap design Ultra high Vacuum Ytterbium oven Lasers and optics Frequency stabilization Necessary electronics Accomplished RF resonator Imaging/ detection Automation/ control system Production of ions Ion trapping Laser cooling Work is in progress Trapping and laser cooling Ultra stable cavity Frequency comb Precision time scale Probing the clock transition ultra stable oscillator - in the pipeline Generation of UTC(NPLI) GPS link with BIPM TWSTFT with NIMs Future!!

23 APMP member Optical clock APMP member Optical clock Australia Ca atom compact clock, Yb atom lattice clock, U. Western Australia Malaysia Bangladesh Nepal Cambodia New Zealand China Ca-ion clock CAS Pakistan Chinese Taipei Guinea S. Korea Yb-atom lattice clock KRISS Philippines Fiji Russia Sr-atom lattice clock VNIIFTRI Hong Kong Singapore India Yb-ion clock NPL Sri Lanka Indonesia Thailand Japan Hg-atom lattice clock U. Tokyo Sr-atom lattice clock RIKEN and NICT Ca, In-ion clock NICT Vietnam