Atom Quantum Sensors on ground and in space

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1 Atom Quantum Sensors on ground and in space Ernst M. Rasel AG Wolfgang Ertmer Quantum Sensors Division Institut für Quantenoptik Leibniz Universität Hannover

2 IQ - Quantum Sensors Inertial Quantum Probes Optical Clocks Quantum Matter

3 IQ - Quantum Sensors Quantum Matter Inertial Quantum Probes Optical Clocks

4 Using atoms as microscopic perfect test masses free falling proof masses Inertial sensing guiding the satellite (laboratory system) Read out of distance or relative motion by optical means, capacitive measurements, or magnetometers

5 Using atoms as microscopic perfect test masses Inertial sensing Quantum Test Absolute Measurement of inertial forces at low frequency Ideal identical test bodies: atoms No charging, no aging effect Sensitivty increases with T 2

6 Cold 87 Rb Sagnac Interferometer Preparation π/2 Interferometer π π/2 3 mm 15 cm A Detection MOT 2 MOT 1 sensitive to both types of inertial forces, rotations and accelerations transportable C. Jentsch, T. Müller, E. Rasel, and W. Ertmer, Gen. Rel. Grav, 36, 2197 (2004) & Adv. At. Mol. Physics

7 Cold Atom Sagnac Interferometer Source 1 atomic source 2 preparation interferometer detection 3D-MOT moving molasses Source 2 2D-MOT

8 time Detuning of the Raman lasers [Hz] Dual interferometry Excitation probability Excitation probability Excitation probability π π/2 C 1 = 24% C 2 = 22% T = 1ms, τ = 7,5µs π/2

9 ϕ rot = 2m Atom h r A Ω r Gyroscope Rotational Sensitivity with 10 8 ats: Ground 10-9 rad/ Expansion Time s Space rad/ Expansion Time 3 s Earth rotation rate: rad/s

10 Accelerometer ϕ acc = T 2 r k a r Accelerational Sensitivity with10 8 ats: Ground g/ Expansion Time 0.2 s Space g/ Expansion Time 3 s

11 IQ - Quantum Sensors Inertial Quantum Probes Optical Clocks Quantum Matter

Feedback Clock Techniques Narrow Transitions Atomic 1mHz - 100 Hz Reference @ 10 10-10 15 Hz Oscillator Lasers Atom-optical Interrogation Techniques & Lasers Monolithic solid

12 Feedback Clock Techniques Narrow Transitions Atomic 1mHz Hz Hz Oscillator Lasers Atom-optical Interrogation Techniques & Lasers Monolithic solid state & for Cooling & Trapping, Preparation, Detection Frequency-stable, compact, reliable Fibre lasers Cavities and Optics Mechanical Design, Miniaturisation & Clock Fibres work

13 Feedback Clock Techniques Narrow Transitions Atomic 1mHz Hz Hz Oscillator Lasers Atom-optical Interrogation Techniques & Lasers Monolithic solid state & for Cooling & Trapping, Preparation, Detection Frequency-stable, compact, reliable Fibre lasers Cavities and Optics Mechanical Design, Miniaturisation & Clock Fibres work

14 Why Mg? Narrow to ultra-narrow transition "Magic" wave length dipole trap ( 1 S 0 3 P 0 : 465 nm) Higher order effects? Reasonable abundance of fermionic and bosonic isotopes 24,25,26 Mg Low black-body shift (10-16 ) Simple electronic structure- easy to model Semi-conductor laser + Frequency Doubling Clock laser: dye laser (200 Hz) diode laser Fast and efficient laser cooling

15 Mg- optical clock- an up date Cooling schemes beyond the Doppler limit 2-photon cooling (500 µk 1D, theore. limit 50 µk) Sisyphus-cooling of the metastable state First frequency measurement in Mg 1 S 0 3 P 1 with a fibre comb generator and a transportable clock of PTB: preliminary value khz (acc < 10-11) New set-up delivering more than 10 9 trapped atoms (loading of about 4*10 8 at/s)

σ(τ=1s)=8,9*10-13 655.660.083.836 khz +/- 3 khz Uncertainty 10-11 Stability: thermal beam 9*10-13 [1s] Ramsey-Bordé-Signal [a.u.

16 σ(τ=1s)=8,9* khz +/- 3 khz Uncertainty Stability: thermal beam 9*10-13 [1s] Ramsey-Bordé-Signal [a.u.] cold atoms 8* [1s] frequency [Hz] 1 st Mg- frequency measurement ν (clock laser)-655,66008 THz [khz] tue. thu measurement no.

17 Effect Shift (Hz) Uncertainty (Hz) Rel. Uncertainty (x10-12 ) 1st order Doppler ,845 2nd order Doppler ,763 2nd order Zeeman ,229 rror Budget Black body radiation DC Stark shift Sagnac effect Total , ,2 0, , , ,161

18 IQ - Quantum Sensors Optical Clocks Quantum Matter Inertial Quantum Probes

19 Dropping BEC

20 Free Fall: up to 9 sec Duration > 1 BEC-Experiment 3 flights per day Implementation Test of a robust BEC Facilities Dimensions < 0.6 x 1.5 m < 234 kg Height 110 m

Bose-Einstein condensates in microgravity, Applied Physics

21 DC-DC transformer Computer control Laser pumps µ-metal shielding QUANTUS Battery pack The QUANTUS Team, Bose-Einstein condensates in microgravity, Applied Physics B: Lasers and Optics, cm

22 4 successfull drops of a magneto-optical trap TKAT

23 Generating BEC External MOT Chip-MOT Moving MOT Molasses Opt. Pumping IP-Trap /Dimple trap Evaporation

24 Increasing phase space Density

25 IQ - Quantum Sensors Optical Clocks Quantum Matter Applications Inertial Quantum Probes

26 Advantages of µ-gravity Extended Time of Evolution Sensitivity ~T 2 Perturbation-free Evolution Ideal inertial reference system No need to compensate gravity / to levitate the atoms Comparison of different species EXTENDED PARAMETER RANGE

relativistic effects & gravity Pioneer anomaly Testing the

27 Atomic Quantum Sensors Fields of Interest: Inertial standards/references Earth Observation Measurement of relativistic effects & gravity Pioneer anomaly Testing the Weak Equivalence Principle Drag-free sensors perhaps in gravitational wave detectors?

28 Dual Atomic Accelerometer 2 atomic species of 10 8 atoms < 1µK combined with a drag free proof mass (Pathfinder or ONERA type / optical read out) Perspectives HYPER orbit Accelerational Sensitivity with 10 8 ats: Space g/ Expansion Time 3 s

29 Pathfinder

30 With cold atoms? Need for Femto-g

31 averaging Scaling factor Averaging T/τ Atomic Temperature an issue and beam splitter velocity : T 2

support Wolfgang Ertmer Theodor Hänsch Thorben Könemann Claus Lämmerzahl Wojciech Lewozko Ronald Mairose Gerrit Nandi

32 Atomic Quantum Sensors Kai Bongs Atom-Chip Wiebke Brinkmann Hansjörg Dittus The BEC-µg Team Robust & Compact Laser Drop Tower & Space Integration DLR 50 WM 0346 Theory Techn. support Wolfgang Ertmer Theodor Hänsch Thorben Könemann Claus Lämmerzahl Wojciech Lewozko Ronald Mairose Gerrit Nandi Achim Peters Peter Prengel Ernst M. Rasel Jakob Reichel Wolfgang Schleich Malte Schmidt Tilo Schuldt Klaus Sengstock Thilo Steinmetz Christian Stenzel Anika Vogel Reinhold Walser Tim van Zoest

33 Thank you for your attention!

34 ENOUGH SPACE FOR EXCITING EXPERIMENTS

Gottfried Wilhelm Leibniz Universität Hannover

Exploring the Potential of Ultra Cold Gases for Fundamental Tests in Space Wolfgang Ertmer Gottfried Wilhelm Leibniz Universität Hannover Institute for Quantum Optics (IQ) Centre for Quantum Engineering