Dynamical effects of exchange symmetry breaking in mixtures of interacting bosons

Abstract

In a double-well potential, a Bose-Einstein condensate exhibits Josephson oscillations or self-trapping, depending on its initial preparation and on the ratio of interparticle interaction to interwell tunneling. Here, we elucidate the role of the exchange symmetry for the dynamics with a mixture of two distinguishable species with identical physical properties, that is, which are governed by an isospecific interaction and external potential. In the mean-field limit, the spatial population imbalance of the mixture can be described by the dynamics of a single species in an effective potential with modified properties or, equivalently, with an effective total particle number. The oscillation behavior can be tuned by populating the second species while maintaining the spatial population imbalance and all other parameters constant. In the corresponding many-body approach, the single-species description approximates the full counting statistics well also outside the realm of spin-coherent states. The method is extended to general Bose-Hubbard systems and to their classical mean-field limits, which suggests an effective single-species description of multicomponent Bose gases with weakly an-isospecific interactions.

Many-particle interference in a two-component bosonic Josephson junction: an all-optical simulation

“…= , so that all particles have the same tunnelling rate Ω and interaction strength U, irrespective of their type, the Hamiltonian is termed isospecific [59].…”

“…In particular, we show that finite inter-particle interaction strengths reduce the many-particle interference contrast by dephasing. A general description of the many-particle dynamics for arbitrary initial states is given in terms of two coupled spins by generalising the Schwinger representation to two particle species.The Schwinger representation is particularly useful under isospecific conditions, since the Hamiltonian (11) of the interacting system can then be brought into the Lipkin-Meshkov-Glick form [59,72] for the total spin J J J A B = +   ˆˆ: H J U J . 1 6 x z 2   = -W +ˆˆ( ) This prompts us to introduce the common eigenstates j m , ñ | of J 2 and J ẑ , which, with the help of the Clebsch-Gordan coefficients C m m m j j j , , , , A B A B…”

“…The Schwinger representation is particularly useful under isospecific conditions, since the Hamiltonian (11) of the interacting system can then be brought into the Lipkin-Meshkov-Glick form [59,72] for the total spin J J J A B = +   ˆˆ: H J U J . 1 6 x z 2   = -W +ˆˆ( ) This prompts us to introduce the common eigenstates j m , ñ | of J 2 and J ẑ , which, with the help of the Clebsch-Gordan coefficients C m m m j j j , , , , A B A B…”

Filtering single atoms from Rydberg-blockaded mesoscopic ensembles

“…Achieving single atom occupation of spatially separated microtraps with high fidelity is more challenging. Several techniques have been explored to reduce the trap occupation number fluctuations [11][12][13][14][15][16][17].…”

Many-body interference in bosonic dynamics

“…So far, only small systems with two modes or two particles were studied from this perspective: e.g. HOM-like interference [44][45][46][47][48][49], the dynamics of a bosonic Josephson junction [50,51] or two-particle quantum walks [52][53][54][55][56].…”