1. T ECHNISCHE U NIVERSITÄT KAISERSLAUTERN Klaas Bergmann Fachbereich Physik and OPTIMAS Forschungszentrum DPG-AMOP Conference -- March 1 st, 2016 -- Hannover

2. STIRAP: basics what is it ? 1 2 3 4 Population transfer between quantum states ….. …. by two photons coupling |1> and |3> via |2> with  on-resonance coupling What STIRAP does: Rev. Mod.Phys. 70, 1003 (98) Is that really of interest ??

3. STIRAP: basics what is it ? 1 2 3 4 (Nearly) complete population transfer between quantum states ….. … without loss despite on-resonance tuning and short lifetime of |2> What STIRAP does: Rev. Mod.Phys. 70, 1003 (98)

4. STIRAP: basics what is it ? 1 2 3 4 Population transfer between quantum states ….. …. or to a coherent superposition of quantum states. What STIRAP does: 3´  ++ -- 11 33  3´ with controlled ratio of population and relative phases  i Rev. Mod.Phys. 70, 1003 (98)

5. STIRAP: basics what is it ? 1 2 3 4 An „enabling technology“ or „methodology" now used in many different physical systems What STIRAP is: -to reach physical conditions for new fascinating experiments (e.g. ultracold molecules and others) -to implement new scheme for quantum technology ( e.g. coupling photons, spins, phonons, including mechanical vibrations ) -to gain access to new ways of doing spectroscpy and precision measurements STIRAP helps (e.g.): Rev. Mod.Phys. 70, 1003 (98)

6. STIRAP: plans what for ? 1 2 3 4 Doing collision dynamic in chemical physics What STIRAP was invented for ? Rev. Mod.Phys. 70, 1003 (98)

7. STIRAP: plans what for ? 326 nm 125 nm v“ = 25 v´ = 8 N2N2 reaction dynamics of molecules in v“ >> 1 relevant for atmospheric chemistry The goal (formulated in 1979): EFFICIENT and SELECTIVE population of highly excited vibrational levels KB: Habil. Thesis (1979) „traditional territory“

8. STIRAP & new territory programm The programm STIRAP basics: The basic features of STIRAP STIRAP in e.g. Solid state physics Ultracold molecules Wave guide optics Cavity QED Trapped ions Molecular Rydberg spectroscopy Precision experiments (eEDM) a very SMALL selection from a large spectrum of topics

9. STIRAP: basics the building blocks The building blocks of STIRAP: STImulated Raman scattering (SRS) Adiabatic Passage (AP) Autler Townes splitting (ATS) Coherent population trapping (CPT) known since  60 years known since > 100 years known since 1955 known since  1952 / 1976 Rev. Mod.Phys. 70, 1003 (98) STIRAP-specific combination

10. STIRAP: basics the Hamiltonian 1 2 3 P S two-photon resonance required detuning  1 from state |2>,  1 = 0 is typical the eigenfunctions INCLUDING the radiative couplings („dressed states) Rev. Mod.Phys. 70, 1003 (98) RWA-Hamiltonian – with radiative coupling bare states adiabatic states 11 coherent population trapping (CPT) dark state ħ  i,k =  i,k E tan  (t) =  P (t)  S (t)

11. STIRAP: basics the dark state 1 2 3 P S |a o > = cos  |1> - sin  |3> key to the transfer: the dark state t = 0 want to start: in |a o >  |1> need  = 0   P = 0 t =  want to end: in |a o >  -|3> need  = 90 o   S = 0 Rev. Mod.Phys. 70, 1003 (98) tan  (t) =  P (t)  S (t)

12. STIRAP: basics the full picture population  energies  S,P 1 2 3 1 2 3 bare states getting started adiab. states Rev. Mod.Phys. 70, 1003 (98) Rabi frequencies adiab. Energies for  = 0 mixing angle populations Time

13. STIRAP: basics the physics elements energies  S,P Rev. Mod.Phys. 70, 1003 (98) one  = 0 other   0 one  <<  max other    max AP  S +  P both    max  S 0  CPT  S (EIT) CPT  P (EIT)  S  S and  P  P Autler-Townes 1 2 3 bare states P S The building blocks

14. STIRAP: basics the dark state |a o > = cos  |1> - sin  |3> 1 2 3 P S Rev. Mod.Phys. 70, 1003 (98) condition for adiabatic evolution:  max T > 10  max T transfer efficiency TE = (100 -  ) % robust against (small) variation of: pulse delay intensity detuning  1 sensitive to detuning from two-photon lasers: excellent coherence needed price to be paid:

15. STIRAP: new territory solid state systems STIRAP in the physics of solid state systems

16. STIRAP: new territory solid state STIRAP in solid state environment The opportunities: confined in space high density of systems scalability The challenges (in all solids): interaction with the lattics short coherence times Praseodym (Pr 3+ Y 2 SiO 5 ) medium for optical storage extremely long storage time 1 Min (Halfmann, TU Darmstadt) T.Halfmann (TU Darmstadt) PRL 111 033601 (2013)

17. STIRAP: new territory solid state = 606 nm 4,6 MHz 4,8 MHz 17,3 MHz 10,2 MHz remove by opt. pumping pump Stokes probe T  4 K STIRAP transfer between Praseodym-states in a Pr:YSO crystal >>  T duration of laser pulse  T  20  s T.Halfmann (TU Darmstadt) PRL 99, 113003 (2007)

18. STIRAP: new territory solid state |a o (t)> = cos  (t) |1> – sin  (t) |3> |a ± (t)> = sin  (t) |1> ± |2> + cos  (t) |3> T.Halfmann (TU Darmstadt) PRA 78, 033416 (2008) S after P  = 90 o initially S before P  = 0 o initially STIRAP plateau

19. STIRAP: new territory NV centers coherent manipulation of spin in Nitrogen vacany (NV) centers Single NV centers are well studied system used for coupling of: nuclear spin electron spin photons (MW and VIS) phonons one of the problem: „spectral diffusion“ of optical transition frequencies structure of NV center solid immersion lens (made by focused ion beam milling) with single NV center (in diamond) near the surface by-passed with STIRAP H.Wang (Eugene/OR)

20. STIRAP: new territory NV centers 2,8 GHz 150 MHz 10 GHz 7,2 MHz  1 GHz  probe EyEy A2A2 0 msms +1 accumulation of thermal population in the ground state (state m s = 0) through optical pumping and non-radiative decay fine structure Zeeman splitting (B-field) hyperfine splitting S P H.Wang (Eugene/OR) PRL 112, 116403 (2014) 637 nm microwave  -pulse |1> |2> |3> start by:

21. STIRAP: new territory NV centers 2,8 GHz 150 MHz 10 GHz 7,2 MHz  1 GHz P S  EyEy A2A2 0 msms +1 1,5  s t rise T (b) (a) (d) (c) T [  s] population transfer S P S P P S one very steep and one shallow slope shaped by acousto-optic modulators H.Wang (Eugene/OR) probe PRL 112, 116403 (2014) T T 637 nm microwave STIRAP-plateau outer steep slope is not detrimental

22. STIRAP: new territory superconduct. circuits STIRAP in a superconducting circuit… …..in a waveguide structure (transmon) „The transmon is the building block of future superconducting quantum processors“ (S. Paraoanu, Aalto) // |3> |2> |1> 4.8 5.3 GHz coherence times recently increased from T c < 1  s to T c  50  s  m m Josephson junction S. Paraoanu group / Aalto Natur comm. 7, 10628 (2016) wicrowave pulses  = phase across the Jos.-junction - oscillating -

23. STIRAP: new territory superconduct. circuits STIRAP in a superconducting circuit….. P1P1 P3P3 P2P2  2,3  1,2  mess  2,3 pulse fixed in time  1,2 pulse delayed in time and ….. …… truncated at t cut which is varied t cut S. Paraoanu group / Aalto Natur comm. 7, 10628 (2016) population measured with pulse starting shortly after t cut Josephson junction

24. STIRAP: new territory ultracold molecules STIRAP in the physics of ultracold molecules

25. STIRAP: new territory ultracold molecules ultracold molecular gases. Work towards…. …… quantum degeneracy in a number of systems: bosonic: 133 Cs 2, 87 Rb 133 Cs and fermionic 40 K 87 Rb, 23 Na 40 K, 23 Na 87 Rb multiple objectives: polar gases: anisotropic interactions mimic & study solid-matter problems new phases of matter: super solids ….. and many more long observation time precision mesurement ultracold chemistry ……. and many more Ch.Nägerl (Innsbruck) H.C.Nägerl

26. STIRAP: new territory ultracold molecules … then do experiments Ch.Nägerl (Innsbruck) many complex experiment steps H.C.Nägerl formation of atomic BEC, load systems into optical lattice (if used) associate atoms through a Feshbach resonance to weakly bound molecules transfer the molecules into the lowest bound state (including hyperfine energy) by STIRAP and ….

27. STIRAP: new territory RbCs Innsbruck ultra cold 87 Rb 133 Cs molecules S P the challenge: finding a suitable intermediate state changing by more than a factor of 10 Ch.Nägerl (Innsbruck) PRL 113, 205301 (2014) E. Tiemann, and others (Dulieu, Hutson, …) 87 Rb 133 Cs

28. STIRAP: new territory RbCs Innsbruck ultra cold RbCs molecules S P detection : absorption imaging of Feshbach molecules done on atomic transition Ch.Nägerl (Innsbruck) PRL 113, 205301 (2014) detect what you have (Feshbach molecules) transfer to ground state transfer back to Feshbach state detect what is left

29. STIRAP: new territory RbCs Innsbruck ultra cold RbCs molecules S P S P 90% efficiency for the transfer Feshbach molecules  ground state similar experiments done by e.g. S. Ospelkaus, Jun Ye et.al. J. Hutson et.al. - and others relatively long interaction time with lasers !! frequency stabilisation needed !! Ch.Nägerl (Innsbruck) PRL 113, 205301 (2014)

30. STIRAP: new territory NaK MIT P S S P ultracold fermionic 23 Na 40 K Special features: Pauli exclusion principle supresses or prevents inelastic collisional loss large dipole moment (2.7 Debye) - controllable by E-field (polarization) temperature T of the order of Fermi-temperatur T F achieved. Goal: T  0.1 T F 75% efficiency for the transfer Feshbach molecules  ground state M.Zwierlein/MIT PRL 114, 205302 (2015) 23 Na 40 K

31. STIRAP: new territory STIRAP in the physics of optical wave guides wave guides

32. STIRAP: new territory wave guides STIRAP puzzle in wave guides 1 2 3 1 2 3 medium coupling 1- 2 medium coupling 2- 3 weak coupling 1- 2 strong coupling 2- 3 medium coupling 1- 2 medium coupling 2- 3 strong coupling 1- 2 weak coupling 2- 3 „STIRAP puzzle“ in waveguides !! ? ? ? STIRAP situation

33. STIRAP: new territory wave guides waveguide array quantum mechanics STIRAP-inspired processes in waveguide physics writing arbitrary wave guide structures with femto second laser pulses S.Longhi – A.Szameit

34. STIRAP: new territory wave guides z |1> |3> |2> P S 1 2 3 transfer of light in a set of three wave guides ? STIRAP-like ? „STIRAP“ in wave guides 1 3 2 S. Longhi (Mailand) S P PRB 76, 201101 (2007) early theoretical work by N. Moiseyev group: IEEE J. Quant. Electronic 37, 1321 (2001)

35. STIRAP: new territory wave guides z |1> |3> |2> S P 1 2 3 „STIRAP“ in wave guides „Rabi“ oscillations here P: (n + ½) Rabi cycles S: n Rabi cycles S. Longhi (Mailand) P S PRB 76, 201101 (2007)

36. STIRAP: new territory AMO continuum transfer briefly back to AMO physics transfer through a continuum ?? intermediate state in continuum should not be populated (STIRAP) electron emission from the intermediate level electron emission related to final state ionisation distinguishable by energy transfer 23 % with proper calibration theory max. 26 % wave guide analogon ? Something close ! T. Halfmann / T. Peters PRL 95, 103601 (2005) tuning across two-photon resonance (GHz) detection of final state population He* He + 1 2 3

37. STIRAP: new territory wave guide „continuum“ closest approach of W 2 A.Szameit et.al. (Jena) Opt. Lett. 34, 2405 (2009) top view output W2W2 W2W2 W1W1 W2W2 input a wide range of the „continuum“ participates in the coupling top view output side continuum participates ? W1W1 intput side discretized „continuum“ closest approach of W 1

38. STIRAP: new territory cavity-QED and ions STIRAP in the physics of cavity QED and trapped ions

39. STIRAP: new territory Cavity QED STIRAP in Cavity -QED |2,0> S |1,0> |3,1> P cavity field laser field Rb coupl.strong enough by vaccuum field A.Kuhn - G.Rempe a single photon/atom added to the cavity field PRL 85, 4872 (2000) developed into single-photon source PRL 89, 067901 (2002) no photon in cavity

40. STIRAP: new territory trapped ions M.Drewsen (Aarhus) STIRAP manipulation of trapped ions Michael Drewsen/Aarhus (24.9.2015 @ STIRAP Symp): “STIRAP has a wealth of applications within cold ion research ! Only time and resources seem to be the limit!“ 4S 1/2 4P 1/2 3D 3/2 |1> 3D 5/2 |3> |2> 4P 3/2 854 nm850 nm 397 nm population of state |1> for STIRAP transfer by optical pumping from 4 S ½ transfer to state |3> by STIRAP when STIRAP works: no population in |2> NJP 8, 261 (2006) Ca + the q-bit

41. STIRAP: new territory trapped ions M.Drewsen (Aarhus) STIRAP manipulation of trapped ions Michael Drewsen/Aarhus (24.9.2015 @ STIRAP Symp): “STIRAP has a wealth of applications within cold ion research ! Only time and resources seem to be the limit!“ 4S 1/2 4P 1/2 |1> |3> |2> detection: 93% from |2> decays to 4 S ½ WHEN transient population in |2> : no STIRAP = fluorescence detected ! NO transient population in |2>: STIRAP = NO fluorescence detected ! NJP 8, 261 (2006) Ca + during transfer:

42. STIRAP: new territory ions M.Drewsen (Aarhus) STIRAP signature of individual ions NJP 8, 261 (2006) individual ions sum of all ions Ca + P S P ahead of S P S STIRAP S-P overlap P S S ahead of P state |2> populated: NO STIRAP state |2> NOT populated STIRAP ! state |2> populated NO STIRAP

43. STIRAP: new territory non-penetrating Rydb. further plans for experiments involving STIRAP in an essential way

44. STIRAP: new territory non-penetrat. Rydberg Spectroscopy of core-NON-penetrating Rydberg states: high-n, high-l CaF …. deviation from Hydrogen-type structure: a sensitive tool for e.g.: precision measurements of properties of molecular ion core l = 0 l  5 How to get there ? vanishing overlap with ground state wavefunction Ca F R.W. Field group - MITR.W. Field / MIT l = 0: core-penetrating l  5: core-NON-penetrating H-like level structure ….

45. STIRAP: new territory non-penetrat. Rydberg X 2  1/2 m + 2 CaF m  < 100 ns 278 nm 910 nm F´ 2  1/2   50 ns n  40  < 5 ns 30 GHz l = 3 l = 4 m + 5  > 100 ns l = 5 fast decay ???? l = 0 l  5 Ca F spectroscopy stepwise ?? R.W. Field group - MITR.W. Field / MIT > n predissociation autoionisation intersystem crossing

46. STIRAP: new territory non-penetrat. Rydberg X 2  1/2 m + 2 CaF m > n  < 100 ns 278 nm 910 nm F´ 2  1/2   50 ns n  40  < 5 ns 30 GHz l = 3 l = 4 m + 5  > 100 ns l = 5 fast decay S P l = 0 l  5 Ca F STIRAP R.W. Field group - MITR.W. Field / MIT spectroscopy experiments in progress at MIT

47. STIRAP physics STIRAP in other fields ( not discussed today ) e.g.: quantum information ( many applications, quantum gates etc. ) P.Zoller, K.Mølmer, C.Wunderlich, W.Hensinger, S.Urabe…….many more optomechanics ( coupling optical and mechanical degrees of freedom) H.Wang/Eugene detecting parity violation in chiral molecules ( detecting feV shifts) M.Quack/ ETH preparation of bright cold atomic beams M.Raizen/Austin spatial adiabatic passage ( matterwave analogon of waveguide features ) J.Mompart/Barcelona, A.Greentree/Melbourne In other processes experiments under way impact of STIRAP on particle physics last topic:

48. electron dipole moment Relevance of STIRAP in the search for an electric dipol moment d e of the electron d e  0  P- and T-symmetry violation standard model (SM) : d e SM < 10 -38 e cm extensions/alternatives to SM: d e SM > 10 -30 e cm from B.N.Spaun, Thesis, Harvard, 2014 Harvard/Yale ACME collab.STIRAP: new territory

49. - 25 -26 -27 -28 -29 -30 -31 -32 -33 -40 -41 10 log d e (e cm) Berkeley 1990 Berkeley 2002 Imperial 2010 Berkeley 1994 ACME 2013 Gen 2 2017 ? Gen 3 STIRAP performance already verified Upper limits to the electron electric dipole moment (eEDM) over the years STIRAP: new territory e EDM Harvard/Yale ACME collab. STIRAP involved in some essential way in Gen 2 + 3 exp.

50. Harvard/Yale ACME collab. STIRAP in precision measurements, here: the electric dipol moment d e of the electron to be measured:  E eEDM = d e E eff E eff enhanced over E ext ( by orders of magnitude ) in molecules due to relativistic effects P. Sandars Phys. Lett. 14, 195 (1965) and 22, 290 (1966) experimental access: precession in B & E fields due to minute energy differences  d e B E  o = 0 B E  o = 0  + (  ) -  - (  ) = 2 d e E eff  2  / h  + (  ) = (  B + d e E eff )  2  / h  - (  ) = (  B - d e E eff )  2  / h Energy-shift = -  B - d e E eff STIRAP: new territory e EDM Energy -shift = -  B + d e E eff t preparation – t detection = 

51. 943 nm 690 nm 1090 nm Thorium-monoxide, ThO 35% Overview: 35% of X(v=0, J =1)  H X 11 A  3 3 H  3 3 C  1 1   500 ns   2 ms detection: H  C  fluorescence long lifetime (for spin precession to proceed) The H-state has perfect properties for e-EDM measurement: small  -doublett splitting  high polarizibility very large enhancement E external  E eff relativistic effect for core-penetrating electrons very small magnetic moment  H < 10 -2  B P.G.H. Sandars Phys.Lett. 14, 194 (1965) Harvard/Yale ACME collab. Science 343, 269 (2014)  = 0 |  | = 1 STIRAP: new territory e EDM

52. Harvard/Yale ACME collab. 943 nm 690 nm 1090 nm Thorium-monoxide, ThO 35% Benefit 1 of STIRAP: efficient population of H state X 11 A  3 3 H  3 3 C  1 1 useable transfer by spontanenous emission:  35% -- spread over 6 states  6 % used < 100% useable transfer by STIRAP:  75 % -- into wanted states  75% used  = 0 |  | = 1 special features: laserpower @ 690 50 mW ( X  C) laserpower @ 1090 10 W (!) ( H  C) two-photon linewidth > Dopplerwidth Cris Panda, Gabrielse group expected total gain through STIRAP: factor 12 STIRAP: new territory e EDM preparation detection Benefit 2 and 3 of STIRAP: for Generation 3

53. Harvard/Yale ACME collabSTIRAP: new territory e EDM -- STIRAP: in the ACME experiment – towards new upper limit of the e-EDM THIS difference may have a significant impact on models in particle physics opt. pumping background preliminary data shown with permission by G. Gabrielse population in the relevant states of the H-level in ThO 10 ms flight time STIRAP population in target state

54. DPG-AMOP Conference -- March 1 st, 2016 -- Hannover T ECHNISCHE U NIVERSITÄT KAISERSLAUTERN Klaas Bergmann Fachbereich Physik and OPTIMAS Forschungszentrum enabling methodology reaching otherwise unaccessible physics-territory Nikolay Vitanov Bruce Shore > 2000 STIRAP publications