We observe solitonic vortices in an atomic Bose-Einstein condensate (BEC) after free expansion. Clear signatures of the nature such defects are twisted planar density depletion around vortex line, observed absorption images, and double dislocation interference pattern obtained through homodyne techniques. Both methods allow us to determine sign quantized circulation. Experimental observations agree with numerical simulations. These decay product phase BEC order parameter spontaneously...

We calculate the excitation spectrum of a one-dimensional self-bound quantum droplet in two-component bosonic mixture described by Gross-Pitaevskii equation (GPE) with cubic and quadratic nonlinearities. The term originates from mean-field energy proportional to effective coupling constant $\delta g$, whereas nonlinearity corresponds attractive beyond-mean-field contribution. properties are governed control parameter $\gamma\propto \delta g N^{2/3}$, where $N$ is particle number. For large...

We discuss quantum annealing of the two-dimensional transverse-field Ising model on a D-Wave device, encoded L×L lattices with L≤32. Analyzing residual energy and deviation from maximal magnetization in final classical state, we find an optimal L dependent rate v for which two quantities are minimized. The results well described by phenomenological powers L-dependent prefactors to describe competing effects reduced fluctuations (for see evidence Kibble-Zurek mechanism) increasing noise...

The dynamic behavior of vortex pairs in two-component coherently (Rabi) coupled Bose-Einstein condensates is investigated the presence harmonic trapping. We discuss role surface tension associated with domain wall connecting two vortices atoms occupying different spin states and its effect on precession pair. results, based numerical solution Gross-Pitaevskii equations, are compared predictions an analytical macroscopic model discussed as a function size pair, Rabi coupling inter-component...

We characterize numerically the dominant dynamical regimes in a superfluid ultracold fermionic Josephson junction. Beyond coherent plasma regime, we discuss onset and physical mechanism of dissipation due to superflow exceeding characteristic speed, provide clear evidence distinguishing its across weakly- strongly-interacting limits, despite qualitative dynamics global characteristics being only weakly sensitive operating dissipative mechanism. Specifically, strongly interacting regime...

We investigate the stability of persistent currents in superfluid fermionic gases confined to a ring geometry. Our study, conducted at zero temperature using time-dependent density functional theory, cover interaction regimes from strong (unitary Fermi gas) weak (Bardeen-Cooper-Schrieffer regime) couplings. Stability is tested against presence an external defect within ring. The dissipation mechanism associated with vortex generation present all regimes. Vortex emission accompanied by Cooper...

We study magnetic solitons, solitary waves of spin polarization (i.e., magnetization), in binary Bose-Einstein condensates the presence Rabi coupling. show that system exhibits two types called $2\pi$ and $0\pi$ characterized by a different behavior relative phase between components. solitons exhibit jump phase, independent their velocity, static domain wall explored Son Stephanov being an example such with vanishing velocity magnetization. instead do not any asymptotic phase. Systematic...

The recent experimental realization of Bose-Fermi superfluid mixtures dilute ultracold atomic gases has opened new perspectives in the study quantum many-body systems. Depending on values scattering lengths and amount bosons fermions, a uniform mixture is predicted to exhibit fully mixed phase, separated phase or, addition, purely fermionic coexisting with phase. occurrence this intermediate configuration interesting consequences when system nonuniform. In work we theoretically investigate...

We study a linear ramp of the nearest-neighbor tunneling rate in Bose-Hubbard model driving system from Mott insulator state into superfluid phase. employ truncated Wigner approximation to simulate quenches uniform 1,2, and 3 dimensions, harmonic trap dimensions. In all these setups excitation energy decays like one over third root quench time. The -1/3 scaling arises an impulse-adiabatic - variant Kibble-Zurek mechanism describing crossover non-adiabatic adiabatic evolution when begins keep...

We study the ground state and excitations of a one-dimensional trapped polarized Fermi gas interacting with single impurity. First, we tunneling dynamics impurity through potential barrier, such as one effectively created by double-well trap. To this end, perform an exact diagonalization full few-body Hamiltonian analyze results in local-density approximation. Off-diagonal one-particle correlation matrices are studied shown to be useful for discerning between different symmetries states....

Low energy physics of quasi-one-dimensional ultracold atomic gases is often described by a gapless Luttinger liquid (LL). It nowadays routine to manipulate these systems changing their parameters in time but, no matter how slow the manipulation is, it must excite system. We study smooth change LL (a "quench") with variable quench and find that excitation decays an inverse power time. This universal exponent -2 at zero temperature, -1 for enough quenches finite temperature. The does not...

We study the attractive Hubbard model with spin imbalance on two lattices featuring a flat band: Lieb and kagome lattices. present mean-field phase diagrams exotic superfluid phases, similar to Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state, whose stability is confirmed by dynamical theory. The nature of pairing found be richer than just Fermi surface shift responsible for usual FFLO state. presence band allows changes in particle momentum distributions at null energy cost. This facilitates...

Reconnecting vortices in a superfluid allows for the energy transfer between different length scales and its subsequent dissipation. The present picture assumes that dynamics of reconnection is driven mostly by phase order parameter, this statement can be justified case Bose-Einstein Condensates (BECs), where have simple internal structure. Therefore, it natural to postulate vicinity moment universal. This expectation has been confirmed numerical simulations BECs experimentally...

We obtain a phase diagram of the spin imbalanced Hubbard model on Lieb lattice, which is known to feature flat band in its single-particle spectrum. Using BCS mean-field theory for multiband systems, we find variety superfluid phases with imbalance. In particular, four different types FFLO phases, i.e. periodic spatial modulation. They differ by magnitude and direction centre-of-mass momentum Cooper pairs. also see large region stable Sarma phase, where density imbalance associated zero pair...

Mott insulator-superfluid transition in a periodic lattice of Josephson junctions can be driven by tunneling rate increase. The resulting winding numbers $W$ the condensate wave function decrease with increasing quench time accord Kibble-Zurek mechanism (KZM). However, very slow quenches, Bose-Hubbard dynamics rearranges wave-function phase so that its random walk cools, $\overline{{W}^{2}}$ decreases and eventually becomes too cold to overcome potential barriers separating different $W$....

A Josephson junction of an ultradilute quantum liquid is studied in a double-well potential. We analyze the dynamics as function interaction strength and compare results to standard bosonic junction. It found that beyond-mean-field effects alter dynamics, particularly regime, where corrections dominate over residual mean-field interaction. In case, we observe non-linear describing localization revivals instead regular oscillations. regime liquids perform oscillations, their frequency also...

We investigate the stability of persistent currents in superfluid fermionic gases confined to a ring geometry. Our studies, conducted at zero temperature using time-dependent density functional theory, cover interaction regimes from strong (unitary Fermi gas) weak (Bardeen-Cooper-Schrieffer regime) couplings. Stability is tested with respect presence an external defect within ring. The dissipation mechanism related vortex generation present all regimes. Interestingly, while corresponding...

We study the Josephson junction made of a one-dimensional ultradilute quantum liquid in double-well potential. analyze dynamics as function interaction strength and compare results to standard bosonic junction. It is found that beyond-mean-field effects alter dynamics, particularly regime, where corrections dominate over residual mean-field interaction. In case, we observe nonlinear describing localization revivals instead regular oscillations. regime liquids perform oscillations, their...

The quantum phase transition from the Mott insulator state to superfluid in Bose-Hubbard model is investigated. We research one, two and three dimensional lattices truncated Wigner approximation. compute both kinetic potential energy they turn out have a power law behaviour as function of rate, with equal 1/3. same applies total system harmonic trap, which usually present experimental set-up. These observations are agreement experiment [8], where such scalings were also observed decay was...

We characterize numerically the dominant dynamical regimes in a superfluid ultracold fermionic Josephson junction. Beyond coherent plasma regime, we discuss onset and physical mechanism of dissipation due to superflow exceeding characteristic speed, provide clear evidence distinguishing its across weakly- strongly-interacting limits, despite qualitative dynamics global characteristics being only weakly sensitive operating dissipative mechanism. Specifically, strongly interacting regime...