Can a gas of spin-up and spin-down fermions become ferromagnetic because repulsive interactions? We addressed this question, for which there is not yet definitive theoretical answer, in an experiment with ultracold two-component Fermi gas. The observation nonmonotonic behavior lifetime, kinetic energy, size increasing interactions provides strong evidence phase transition to state. Our observations imply that itinerant ferromagnetism delocalized possible without lattice band structure, our...

The recombination of two split Bose-Einstein condensates on an atom chip is shown to result in heating which depends the relative phase condensates. This reduces number condensate atoms between 10% and 40% provides a robust way read out interferometer without need for ballistic expansion. may be caused by dissipation dark solitons created during merging

We describe the formation of fermionic NaLi Feshbach molecules from an ultracold mixture bosonic ${}^{23}$Na and ${}^{6}$Li. Precise magnetic field sweeps across a narrow resonance at 745 G result in molecule conversion fraction $5%$ for our experimental densities temperatures, corresponding to number $5\ifmmode\times\else\texttimes\fi{}{10}^{4}$. The observed molecular decay lifetime is $1.3$ ms after removing free Li Na atoms trap. Due its extremely low reactivity, ground state will have...

Elongated Bose-Einstein condensates (BECs) exhibit strong spatial phase fluctuations even well below the BEC transition temperature. We demonstrate that atom interferometers using such are robust against fluctuations; i.e., relative of split condensate is reproducible despite axial fluctuations. However, larger limit coherence time, especially in presence some asymmetries two wells interferometer.

Fermi gases with repulsive interactions are characterized by measuring their compressibility as a function of interaction strength. The is obtained from in-trap density distributions monitored phase-contrast imaging. For parameters ${k}_{F}a>0.25$, fast decay the gas prevents observation equilibrium profiles. smaller parameters, results adequately described first-order perturbation theory. We have developed imaging method that compensates for dispersive distortions images.

Imaging an object embedded within a scattering medium requires the correction of complex sample-induced wave distortions. Existing approaches have been designed to resolve them by optimizing signal waves recorded in each 2D image. Here, we present volumetric image reconstruction framework that merges two fundamental degrees freedom, wavelength and propagation angles light waves, based on momentum conservation principle. On this basis, propose methods for exploiting correlation from images...

Compensation of sample-induced optical aberrations is crucial for visualizing microscopic structures deep within biological tissues. However, strong multiple scattering poses a fundamental limitation identifying and correcting the tissue-induced aberrations. Here, we introduce label-free deep-tissue imaging technique termed dimensionality reduction adaptive-optical microscopy (DReAM) to selectively attenuate scattering. We established theoretical framework in which time-gated reflection...

We show how to use trapped ultracold atoms measure the magnetic susceptibility of a two-component Fermi gas. The method is illustrated for noninteracting gas ${}^{6}$Li, using tunability interactions around wide Feshbach resonance. versus effective field directly obtained from inhomogeneous density profile atomic cloud. wings cloud realize high-field limit where polarization approaches 100$%$, which not accessible an electron

Shaping the wavefront of an incident wave to a complex scattering medium has demonstrated interesting possibilities, such as sub-diffraction focusing and light energy delivery enhancement. However, shaping mainly been based on control transmitted waves that are inaccessible in most realistic applications. Here, we investigate effect maximizing backscattered at specific flight time propagation dynamics transport. We find both experimentally numerically maximization short focuses particles...

In complex media, light waves are diffused both in space and time due to multiple scattering, its intensity is attenuated with the increase of propagation depth. this paper, we propose an iterative wavefront shaping method for enhancing time-gated reflection intensity, which leads efficient energy delivery a target object embedded highly scattering medium. We achieved over 10 times enhancement reflectance at specific flight demonstrated focusing object. Since proposed does not require matrix...

A novel high-throughput second-order-correlation measurement system is developed which records and makes use of all the arrival times photons detected at both start stop detectors. This suitable particularly for a light source having high photon flux long coherence time since it more efficient than conventional methods by an amount equal to product count rate correlation source. We have used this in carefully investigating dead effects detectors counters on second-order function two-detector...

Optical imaging of objects embedded within scattering media such as biological tissues suffers from the loss resolving power. In our previous work, we proposed an approach called collective accumulation single (CASS) microscopy that attenuates this detrimental effect multiple light by combining time-gated detection and spatial input-output correlation. present perform a rigorous theoretical analysis on to optical transfer function CASS microscopy. particular, frequency-dependent signal noise...

In many complex physical phenomena such as wave propagation in scattering media, the process of interest often cannot be easily distinguished from other processes because only total combined is accessible. This makes it difficult to extract precise knowledge each subprocess. Here, we derive an analytic expression describing way eigenchannel coupling distributes its energy individual subprocesses, with partial information on subprocess average eigenvalue 〈τ〉 and enhancement factor η. We found...

Light waves propagating through complex biological tissues are spatially spread by multiple light scattering, and this limits the working depth in optical bioimaging, phototherapy, optogenetics. Here, we propose iterative phase conjugation of time-gated backscattered for enhancing energy delivered to a target object embedded scattering medium. We demonstrate enhancement hidden behind 200-µm-thick mouse skull more than ten times comparison with initial random input. The maximum was reached...

Ho claims in his comment that our experiment is direct evidence itinerant ferromagnetism does not exist ultracold Fermi gases. This claim incorrect and based on an invalid estimate of relaxation times erroneous interpretation the detectability ferromagnetic domains. We point out experimental consistent with existence ferromagnetism, but further experiments are needed to distinguish a ground state from non-magnetic correlations.

To exploit photonics technologies for in vivo studies life science and biomedicine, it is necessary to efficiently deliver light energy the target objects embedded deep within complex biological tissues. However, waves diffuse randomly inside media due multiple scattering, only a small fraction reaches object. Here we present method counteract random diffusion focus 'snake-like' multiple-scattered target. realize this, experimentally identified time-gated reflection eigenchannels that have...

When light propagates through a scattering media, energy is exponentially attenuated due to random diffusion by multiple scattering. Here, we present method focus the target deeply embedded in medium control of time-gated scattered waves. In comparison with case diffusion, could demonstrate 10-fold enhancement delivery rat skull.