Atom Chips and Photonic Crystals Chiara Fort Francesco Cataliotti Diederik Wiersma Francesco Marin

Ultracold Atoms and Optical Lattices Traditional Systems Current ~ 100 A Power ~ 1.5 kW n = 10-100 Hz + Ultra High Vacuum ~ 10-11 Torr double MOT system: Laser power ~ 500 mW Large BEC 106 atoms but production cycle > 1 min Well established experimental procedure, possibility of working with large atomic samples, very well proven versatility Low repetition rate, complicated and expensive, single site access problematic

Atom Chips and Photonic Crystals Novel Technology Micro-chip traps Photonic Crystals + Silicon: 2 cm x 3 cm x 600 mm Gold microwires: 2.5 mm X 50 ~ 300 mm Currents: < 2 A single MOT system: Laser power ~ 100 mW Fast and cheap experiments, extreme versatility, possibility of single site addressing, cross fertilization from different active fields “Small” atomic samples, Mixtures yet to be proven, New technologies involved

Outlook Cooling and trapping Atoms on a Microchip Photonic materials Photonic BEC? Conclusions

Degenerate Atoms (road to work) 1925: Einstein predicts “condensation” of bosons 60’s: Development of Lasers 80’s: Development of laser cooling 1985: Magnetic Trapping of ultracold atoms 1986: Optical trapping of Na 1987: Na Magneto-Optical Trap 1995: First 87Rb Bose-Einstein Condensate Huge playground for fundamental physics: BEC with Li, Na, K, Cs, Fr… Optical gratings, collective excitations… First applications: Interferometry Earth and Space sensors Quantum Information 2001: First BEC of 87Rb on an Atom Chip

Loading atoms on a microchip Ridurre la distanza tra la MOT e il MicroChip. s+ s- s+ s- s+ s-

Loading atoms on a microchip

Trapping atoms on a Chip Planar Geometry  gold microstrips on silicon substrates Bwir (Iwir= 3A) Bbias = {0,3.3,1.2} Gauss |B| (Gauss) z (mm) Iwir= 3 A ; Bbias= {0,3.3,1.2} Gauss Iwir= 1 A ; Bbias= {0,3.3,1.2} Gauss |B| (Gauss) x (mm)

Trapping atoms on a Chip Quadrupole trap (B=0 at minimum) - Good for magneto-optical traps Ioffe-Pritchard trap (B>0 at minimum) - Good for magnetic trapping. ΔE m=1 Magnetically trapped state m=0 |B| m=-1

Trapping atoms on a Chip

Trapping atoms on a Chip Varying the current on the chip it is possible to manipulate the atoms Chip realized in AtomInstitut in Vienna. Assembled at INFN by E. Scarlini, I. Herrera and L. Consolino

Trapping atoms on a Chip

Photonic Materials Photonic crystals are periodic optical (nano)structures that are designed to affect the motion of photons in a similar way that periodicity of a semiconductor crystal affects the motion of electrons. Photonic crystals occur in nature and in various forms have been studied by science for the last 100 years.

Photonic Materials Multiple light scattering and optical amplification - Lasing based on trapping of light in random systems - Fundamental physics: Anderson localization of light - Mechanism behind lasing understood, Levy statistics - Applications under development in photonic devices and sensing Local micro-infiltration of liquids (water) in 2D photonic crystals - New technology to realize photonic circuits - Rewritable and flexible structures (combine sources, switches, waveguides,…) - Locally controlled infiltration with 100 nm accuracy - Based on NSOM, confocal microscopy

Photonic Materials Integrated waveguides Using nanostructured materials it is possible to create photonic structures to realize either planar or linear waveguides. By getting the atoms at micrometric distances from the structured surface we will be able to make them interact with the evanescent wave field leaking out of similar waveguides. We will be able to efficiently address the atoms with different optical wavelengths creating both repulsive and attractive potentials. the ability to use different light colours in the waveguides will also enable us to create a various potential geometries going from purely periodic to quasi periodic with the possibility of generating very well controllable time dependent potentials.

Conclusions The atoms will be brought in the evanescent field of micro and nanostructures Reproducible potentials for atoms will be realized Modification of optical properties of structures will be possible Very small atom-surface distances Small index of refraction of atomic samples

Photonic BEC Mirror mass M ≈ 10-20 Kg Mirror Temperature T = 0 K When atoms are trapped in the periodic structure formed by an optical lattice, the stystem behaves as a Bragg mirror in its ground state Mirror mass M ≈ 10-20 Kg Mirror Temperature T = 0 K Reflectivity Bandwidth Physical Review Letters 104, 050403 (2010)

Coherent optical information storage in cold atoms (with P. Lombardi, F. Marin and E. Giacobino) C. Liu, Z. Dutton, C. H. Behroozi, L. Hau Nature 409, 490 (2001)

Utilizzo personale e strutture Studenti: Pietro Lombardi (Dott.) Francesco Cappelli (LS) Personale strutturato: Chiara Fort Francesco Cataliotti (DE) Francesco Marin Massimo Inguscio Personale non strutturato: Ivan Herrera (LENS) Jovana Petrovic (LENS) Impatto Dipartimento: Assistenza microsaldatura e micromanipolazione per assemblaggio (1 – 2 settimane x anno) (Enrico Scarlini)

Pubblicazioni (dal 2007) “Magnetic microtraps for quantum control” I. Herrera, G. D’Arrigo, M. Siciliani de Cumis, F. S. Cataliotti International Journal of Quantum Information 5, 23-31 (2007) “Modeling the dynamics of a weakly coupled chain of quantum systems” F. S. Cataliotti, L. Fallani, F. Ferlaino, C. Fort, P. Maddaloni, M. Inguscio. New Journal of Physics 10th Anniversary Highlights 14 (2008) “Interferometric quantum sensors” M. Siciliani de Cumis, F. Marino, M. Anderlini, F. S. Cataliotti, F. Marin, E. Rimini, G. D’Arrigo Advances in Science and Technology 55 154-159, (2008) “Macroscopic Quantum Entanglement in Light Reflection from Bose-Einstein Condensates” F. De Martini, F. Sciarrino, N. Spagnolo, C. Vitelli, F. S. Cataliotti International Journal of Quantum Information 7, 171-177 (2008) “Radiation pressure excitation and cooling of a cryogenic micro-mechanical systems cavity” M. Siciliani de Cumis, A. Farsi, F. Marino, G. D'Arrigo, F. Marin, F.S. Cataliotti, E. Rimini Journal of Applied Physics 106(1), 013108, (2009). “Hidden order in bosonic gases confined in one dimensional optical lattices” L. Amico, G. Mazzarella, S. Pasini and F.S. Cataliotti New Journal of Physics . 12, 013002 (2010). “Coherent scattering of a Multiphoton Quantum Superposition by a Mirror-BEC” F. De Martini; F. Sciarrino; C. Vitelli and F.S. Cataliotti Phyical Review Letters, 104, 050403 (2010). “Classical signature of ponderomotive squeezing in a suspended mirror resonator” F. Marino, F. S. Cataliotti, A. Farsi, M.Siciliani de Cumis and F. Marin Phyical Review Letters, 104, 073601 (2010).