Neven Šantić

Institute of Physics, Zagreb

Synthetic magnetism in cold atomic gases opened the doors to many exciting novel physical systems and phenomena. Ubiquitous are the methods used for the creation of synthetic magnetic fields. They include rapidly rotating Bose-Einstein condensates employing the analogy between the Coriolis and the Lorentz force, and laser-atom interactions employin...

We theoretically predict a novel type of synthetic Lorentz force for classical (cold) atomic gases, which is based on the Doppler effect and radiation pressure. A fairly uniform and strong force can be constructed for gases in macroscopic volumes of several cubic millimeters and more. This opens the possibility to mimic classical charged gases in m...

We experimentally investigate the radiative force and laser-induced fluorescence (LIF) in cold rubidium atoms induced by pulse-train (frequency-comb) excitation. Three configurations are studied: (i) single-pulse-train excitation, (ii) two in-phase counterpropagating pulse trains, and (iii) two out-of-phase counterpropagating pulse trains. In all c...

We demonstrate a cavity-based solution to scale up experiments with ultracold atoms in optical lattices by an order of magnitude over state-of-the-art free-space lattices. Our two-dimensional (2D) optical lattices are created by power-enhancement cavities with large mode waists of 489(8)μm and allow us to trap ultracold strontium atoms at a lattice...

We demonstrate a cavity-based solution to scale up experiments with ultracold atoms in optical lattices by an order of magnitude over state-of-the-art free space lattices. Our two-dimensional optical lattices are created by power enhancement cavities with large mode waists of 489(8) $\mu$m and allow us to trap ultracold strontium atoms at a lattice...

We report on a compact, ultrahigh-vacuum compatible optical assembly to create large-scale, two-dimensional optical lattices for use in experiments with ultracold atoms. The assembly consists of an octagon-shaped spacer made from ultra-low-expansion glass, to which we optically contact four fused silica cavity mirrors, making it highly mechanically...

We report on an ultrahigh-vacuum compatible optical assembly to enhance the optical power of two separate laser beams with the aim of creating large-scale, two-dimensional optical lattices for use in experiments with ultracold atoms. The assembly consists of an octagon-shaped spacer made from ultra-low-expansion glass, to which we optically contact...

We demonstrate state-dependent optical lattices for the Sr optical qubit at the tune-out wavelength for its ground state. We tightly trap excited state atoms while suppressing the effect of the lattice on ground state atoms by more than 4 orders of magnitude. This highly independent control over the qubit states removes inelastic excited state coll...

We demonstrate state-dependent optical lattices for the Sr optical qubit at the tune-out wavelength for its ground state. We tightly trap excited state atoms while suppressing the effect of the lattice on ground state atoms by more than four orders of magnitude. This highly independent control over the qubit states removes inelastic excited state c...

We report on laser cooling of neutral rubidium atoms by using a single mode of a frequency comb. Cooling is achieved on a dipole-allowed transition at 780 nm in a one-dimensional retro-reflected beam geometry. Temperatures are measured using standard time-of-flight imaging. We show the dependence of the temperature on the cooling time, intensity an...

The nonlinear Schrödinger equation, used to describe the dynamics of quantum fluids, is known to be valid not only for massive particles but also for the propagation of light in a nonlinear medium, predicting condensation of classical waves. Here we report on the initial evolution of random waves with Gaussian statistics using atomic vapors as an e...

We report the observation of nonequilibrium precondensation of light propagating in atomic vapors. At variance with complete thermalization requiring prohibitive interaction lengths, this effect occurs by a fast relaxation to a precondensate state.

We implement a synthetic Lorentz force in a cold atomic gas released from a magneto-optical trap. The signature of this is an angular deflection of a rotationally asymmetrical cloud. The effect is a consequence of thermal expansion of the cold atomic cloud under the influence of the applied synthetic Lorentz force. The synthetic Lorentz force is ba...

We study the radiation pressure force exerted on cold 87Rb atoms captured in a magneto-optical trap (MOT) due to resonant excitation of atoms into the non-cooling 5P1 / 2(F e = 2) hyperfine level. We measure the fractional excited population for different MOT parameters such as cooling laser detuning and power, and empirically test the applicabili...

We propose a source for high-brightness ion and electron beams based on the ionization of an effusive atomic beam which is transversely laser cooled and compressed. The very low transverse temperature (mK range) and the relative low density of the starting atomic sample ensure excellent initial conditions for obtaining bright and monochromatic char...

It is usually assumed that the quantum step (QS), quantum well (QW) and quantum barrier (QB) have the rectangular potential profiles. We show that the potential profiles are not really rectangular. A QS is actually a smooth, gradual change of potential over a distance larger than one monolayer. For a narrow QW, instead of the QW, a more appropriate...