• Abstracts

    Ben Aicha, Yosri — Bragg-Based Atom Interferometry with Overlapped Spatial Fringes

    Bragg-based atom interferometry is the standard technique for atom interferometry using Bose-Einstein condensates as an atomic source. However, as it is unable to distinguish between the two output ports of the interferometer at the final beam splitter pulse, a minimum separation time between the two clouds is required. This reduces the interferometer time compared to Raman methods for a given device size. We present a measurement technique to reduce this separation time by monitoring the phase between a spatial reference and overlapped spatial fringes arising from an asymmetrical Mach-Zehnder interferometer.

  • Abstracts

    He, Yuanlei — Multifrequency Slower for MOT

    This project will give an approach to using multiple frequencies of light to enhance the loading of a Magneto-Optical Trap (MOT). An electro-optical modulator will be used to produce frequency and intensity tunable sidebands, enabling the nature of slowing to be controlled, and thus optimized, by the user. There are some basic computational simulations that have been done so far. The motivation for this project and some basic ideas will be introduced in this presentation.

  • Abstracts

    Favalli, Tommaso — Time from Quantum Entanglement

    The idea that time may emerge from quantum entanglement originated from a mechanism proposed in 1983 by Don Page and William Wootters to solve the, so called, “problem of time” that arises in the context of canonical quantization of gravity. The Page and Wootter (PaW) theory consists in dividing the total Hilbert space into two sub-systems and assigning one of it to time. The “flow of time” then consists simply in the entanglement between the quantum degree of freedom of time and the rest of the system, a correlation present in a global, time-independent state. In this framework we do not consider time as an abstract, external coordinate, but as…

  • Abstracts

    Ruhl, Joanna — Lagrange bracket approach to quantum fluctuations in macroscopic parameters of NLS breathers

    In the focusing nonlinear Schrodinger equation, multisoliton ”breathers” may be created from a single mother soliton by quenching the strength of the nonlinear interaction. In ultracold-gas realizations, atop the mother soliton there are quantum fluctuations coming from its underlying quantum many-body nature, computable from the Bogoliubov theory. Post-quench, these fluctu- ations become the fluctuations in the macroscopic parameters of the daughters, which exist in a coherent macroscopic quantum state. We present a mean-field formalism that uses Lagrange brack- ets to compute, from given pre-quench fluctuations, the fluctuations of the macroscopic parameters of the daughter solitons, with results for both the 2-soliton and 3-soliton breathers.

  • Abstracts

    de Almeida, Alexandre A. C. — Generation of correlated forward four-wave mixing signals with cold atoms

    We report preliminary results on the generation of two correlated Forward Four-Wave Mixing (FFWM) signals using cold rubidium atoms. To induce the FFWM process, we use two almost copropagating beams, with linear and orthogonal polarization. We calculate the time-delay intensity correlation function between all four fields to detect correlation and anticorrelation. In addition, the spectral lineshape of the FFWM signals presents an interesting feature. If one scans the frequency of both input beams simultaneously, the spectra will present a dip around the resonance due to the coherent population trapping. We use a simple three-level lambda system and solve the Bloch equations to model this feature.

  • Abstracts

    Richaud, Andrea — Vortices with massive cores in a binary mixture of BECs

    We analyze a notable class of states relevant to an immiscible bosonic binary mixture loaded in a rotating boxlike circular trap, i.e., states where vortices in one species host the atoms of the other species, which thus play the role of massive cores. The resulting effective Lagrangian resembles that of charged particles in a static electromagnetic field, where the canonical momentum includes an electromagnetic term. The simplest example is a single-vortex system. While a massless vortex can only precess uniformly, the presence of a sufficiently large filled vortex core renders such precession unstable. A small core mass can also enhance the orbit radius or lead to small radial oscillations, which…

  • Abstracts

    Safeer, S S — Design and development of Electronics modules for a Compact Cold Atom Inertial System

    Research aim is to develop a compact electronics module for a cold atom interferometer based system using Rubidium atoms (780nm). Laser systems are one of the most critical part of the cold atom system as they have to be stable in terms of optical power, frequency, line width and spectral properties and should also be a compact system. It is also required to control modulator drivers, RF drivers and detection systems by suitably pulsing the devices as per the requirement of the measurement system. In laboratory-based set ups, these devices are accommodated in multiple electronics racks and transportation of the systems will be a bit difficult. Hence, it is proposed…

  • Abstracts

    Famà, Francesca — Towards continuous superradiance with a hot atomic beam

    Continuous superradiant lasers have been proposed as next generation optical atomic clocks for precision measurement, metrology, quantum sensing and the exploration of new physics [1]. Superradiance is a collective phenomenon resulting in an enhanced single atom emission rate [2]. A way to provide the required phase synchronization is coupling a cold cloud of atoms to a cavity mode. This technique has been used to demonstrate pulsed superradiance [3-5], however, steady-state operation remains an open challenge. Here we describe our machine aimed at validating an alternative proposal [6], a rugged superradiant laser operating on the 1S0-3P1 transition of 88Sr using a hot collimated atomic beam. The elegance of this approach is…

  • Abstracts

    Hanımeli, Ekim T. — Combining Bragg and Raman processes for novel interferometry topologies

    Bragg and Raman are the two most important techniques to form beam splitters in atom interferometry. While often used for the same purpose, the two techniques have different physical characteristics that can be exploited in different ways. This allows two methods to be combined to create interesting novel interferometry topologies, such as quantum clock interferometry. In this presentation I will talk about some of the possibilities that utilize a combination of Bragg and Raman transitions, and the new laser system built for Quantus-1 that is able to implement both processes.

  • Abstracts

    de Almeida, Ricardo Costa — Entanglement certification of many-body systems with quench dynamics

    Entanglement is central to the modern understanding of quantum systems and the primary resource for upcoming quantum technologies. However, a potential bottleneck for future advances is the need for scalable protocols to detect and characterize entanglement. In particular, there is an increasing demand for procedures that can certify the presence of entanglement in quantum many-body systems. The quantum Fisher information(QFI) is a witness for multipartite entanglement of great relevance to quantum metrology. Unfortunately, it is hard to estimate the QFI so its use as a tool for entanglement certification is limited, for now. In this talk, we discuss recent works that address this issue and demonstrate that the QFI can…