Fragmentation of a spin-1 mixture in a magnetic field

Abstract

We study the ground state quantum fragmentation in a mixture of a polar condensate and a ferromagnetic condensate when subject to an external magnetic field. We pay more attentions to the polar condensate, due to the fact that the fragmentation of polar condensate, which typically occurs only in a very weak magnetic field, can occur in the mixture at higher magnetic fields, where both atom numbers and the number fluctuations will keep in a macroscopic magnitude of order of N . The role of the ferromagnetic condensate is to provide a uniform and stable background which can delay the rapid shrink of the 0-component population and make it possible to capture the "super-fragmentation ". Our method has potential applications in measuring the inter-species spin-coupling interaction through adjusting the magnetic field.

Concise analytic solutions to the quantum Rabi model with two arbitrary qubits

“…We stress that the present analytic solution is well defined mathematically, because of no built-in truncations, which is essentially different from the previous finite truncation approaches [11,16,17] and the continued-fraction technique, therefore of both fundamental and practical interest.…”

“…Such a model system with two qubits now can be constructed in several solid devices [8][9][10]. Recently, some analytical studies to the QRM with two qubits have been attempted within various approaches [11][12][13][14][15][16][17]. By using the ECS technique, a G-function for the QRM with two equivalent qubits, resembling the simplest one without a determinant in the single-qubit QRM [2], was obtained [15].…”

Heteronuclear magnetisms with ultracold spinor bosonic gases in optical lattices

“…Away from the deep Mott-insulating regime, which is frequently encountered in experiments, quantum fluctuations become more and more important with the increase of tunneling amplitudes; until finally the tunneling dominates in the superfluid regime with φ 1 αm = 0 (see definition in Table I, and magnetism of weakly interacting bosons can be found in Ref. [19][20][21][22][23]. These fluctuation effects can be naturally included in our BDMFT approach.…”

“…Model and Degeneracy. Under the single mode approximation [19][20][21][22][23], the 3D lattice can be described by the following generalized BH model (see details in Ref. 24),…”

Ground-state phases of a mixture of spin-1 and spin-2 Bose-Einstein condensates

“…We expect that a mixture of such spinor BECs will exhibit novel quantum phases and topological excitations. A spin-1/spin-1 mixture has been studied theoretically and phase diagrams and many-body properties have been determined [19][20][21][22][23][24][25][26][27][28][29]. The spin dynamics in a mixture of a spin-1 23 Na BEC and a spin-1 87 Rb thermal gas have been observed experimentally [30].…”