• Abstracts

    Simulation of wavefront propagation for a cold atoms gravimeter (Pesche, Maxime)

    A cold atoms gravimeter il a device which measure the gravity with Raman transitions on free falling atoms. Since 2006, the SYRTE research team is working on such a gravimeter, and during my thesis, I will continue their work. Today, this gravimeter is working with an accuracy of 5.7 10^-8. The limits on this result are known: the wavefront aberration. The combination of the velocity distribution of the atoms and the irregularity of the optics create a complicated to evaluate bias on g which fluctuate in time. This cause a degradation of the accuracy and the long term stability. In this talk, I will present the work I did during…

  • Abstracts,  Presentations

    Weak values in the study of quantum correlations (Zamora, Santiago)

    (Physics Institute, UNAM) Abstract Weak values have become of interest in recent years due to their several applications and their succesful experimental realization. Among their applications, they are useful in the theoretical detection of quantum correlations. In this talk I will present the general idea of what is a weak value and a quantum entanglement criterion for a system of 2 particles in a pure state using the weak values formalism. Slides

  • Abstracts

    Brimis, Apostolos — Tornado waves

    Structured light has recently attracted the interest of scientific society while it is possible to control it in all its degrees of freedom and dimensions. I will present light spiraling like a tornado over its propagation. Such structured light can be generated by superimposing abruptly auto- focusing ring-Airy beams that carry orbital angular momentum of opposite handedness. This results to a complex wave with intense lobes that twist and shrink in an accelerating fashion along propagation. [1] A. Brimis, K. G. Makris, and D. G. Papazoglou, “Tornado waves,” Opt. Lett.45, 280–283 (2020). [2] Dimitris Mansour, Apostolos Brimis, Konstantinos G. Makris and Dimitris G. Papazoglou, "Generating Spiraling Light: Optical Tornados "…

  • Abstracts

    Simonsen, Veronica P. — The NanoLace project: Grid-based holograms for matter waves lithography

    Grid-based binary holography (GBH) is an attractive method for patterning with light or matter waves. It is an approximate technique in which different holographic masks can be used to produce similar patterns. Mask-based pat- tern generation is a critical and costly step in microchip production. The next- generation extreme ultraviolet- (EUV) lithography instruments with a wave- length of 13.5 nm are currently under development. In principle, this should allow patterning down to a resolution of a few nanometers in a single expo- sure. However, lithography with metastable atoms has been suggested as a cost-effective, less-complex alternative to EUV lithography. The great advan- tage of atom lithography is that the kinetic…

  • Abstracts,  Presentations

    Sinkevičienė, Mažena Mackoit — Quantum metrology: from solids to cold atoms

    k I will touch two directions of my research: color centers in solids that I have investigated during my PhD studies and cold atom systems that I am going to investigate during my Postdoc. First, I will present my studies of solid-state systems capable of emitting non-classical states of light. Subsequently I will briefly describe the idea of creating the non-classical spin states and spin squeezing for the cold fermionic atoms in optical lattices by applying the spin-orbit coupling and the periodic driving of the system.

  • Abstracts

    Faraji, Elham — Properties of electronic currents along DNA fragments through light pumping

    We are working on a model partly borrowed from the standard Davydov-Fröhlich models originally introduced to account for electron-phonon interaction in macromolecules. Under the action of an external electromagnetic field on a DNA protein, the energy transferred to the electron shows an electronic current which can display either a spreading frequency spectrum or a sharply narrow frequency spectrum. This phenomenology displays a potentially rich variety of electrodynamic interactions of DNA molecules by the electron excitation. This could imply the activation of interactions between DNA and external electromagnetic fields.

  • Abstracts

    Li, Vyacheslav — Frequency offset locking

    Applications of lasers in quantum metrology require precise control of the laser frequency. This is usually achieved by locking the frequency of a slave laser at a tunable offset from a master laser. Here we present a new scheme for a robust and high precision laser offset frequency locking. A hybrid frequency discriminator generates an error signal that has a wide capture range of more than 180 MHz while preserving sharp resonance needed for a tight lock. The Allan deviation was measured to be less than 12 Hz at 1 seconds and remained below 1 kHz for more than 1000 seconds.

  • Abstracts

    Wilson, Gwyn — Resonant Transmission in Smooth Barriers

    Resonant transmission is a well-known effect in quantum mechanics, often studied in undergraduate physics courses. There is a resonant behaviour in the transmission probability for a square barrier potential. However, this effect is not seen in a gaussian barrier. The lack of resonances is investigated for barriers that start with a square shape and are deformed into a smoother one, with the transmission probability being calculated numerically. Doing so gives insight into the behaviour of the resonances and how the barrier shape can affect their presence.

  • Abstracts

    Kristensen, Sofus Laguna — Properties of Raman beamsplitters using phase modulated light in an optical cavity

    Using an optical cavity to perform atom interferometry offers several advan- tages; the high-quality wavefronts allows for very long coherence time (20 s) of a spatially seperated superposition held in an optical lattice, and the resonant power enhancement allows the use of simpler laser systems with a fiber opti- cal modulator to generate laser frequency pairs that are needed for performing Raman beamsplitters. However, these frequency components form multiple standing waves in the cavity, resulting in a periodic spatial variation of the properties of the atom-light interaction along the cavity axis. Here, we will describe this spatial dependence and calculate two-photon Rabi frequencies and ac Stark shifts, and confront the…