Elimination of the degenerate trajectory of a single atom strongly coupled to a tilted TEM10cavity mode

Abstract

We demonstrate the trajectory measurement of the single neutral atoms deterministically using a high-finesse optical microcavity. The single atom strongly couples to the high-order transverse vacuum TEM 10 mode, instead of the usual TEM 00 mode, and the parameters of the system are (g 10 ,κ,γ ) = 2π × (20.5,2.6,2.6) MHz. The atoms simply fall down freely from the magneto-optical trap into the cavity modes, and the trajectories of the single atoms are linear. The transmission spectra of atoms passing through the TEM 10 mode are detected by single-photon counting modules and are well fitted. Thanks to the tilted cavity transverse TEM 10 mode, which is inclined to the vertical direction ∼45 • , it helps us to eliminate the degenerate trajectory of the single atom falling through the cavity and to obtain a unique atom trajectory. An atom position with a high precision of 0.1 µm in the off-axis direction (axis y) is obtained, and a spatial resolution of 5.6 µm is achieved in a time interval of 10 µs along the vertical direction (axis x). The average velocity of the atoms is also measured from the atom transits, which determines independently the temperature of the atoms in a magneto-optical trap, 186 ± 19 µK.

Fundamental Tests of Physics with Optically Trapped Microspheres

“…A recent experiment also used a tilted cavity TEM10 mode to measure the trajectories of single neutral atoms deterministically [130].…”

Fragmentation of a spin-1 mixture in a magnetic field

“…Away from the critical point, the system is dominated by the magnetic field with the magnetization m 2 = n 1 − n −1 increased linearly. The negative γ term encourages pairing two different types of atoms into singlets [10]. In Fig.…”

“…We consider the direct product of the Fock states of the two species |n 1 , n 0 , n −1 1 ⊗ |n 1 , n 0 , n −1 2 , and do not restrict the model in the subspace with zero total magnetization [9,10]. Instead, we consider the full space including all possible system magnetization m = m 1 + m 2 .…”

“…However, we can numerically study the phase transition through the order parameter Θ † 12Θ 12 [10]. To see more clearly the role played by the parameter c 12 γ on the fragmentation, we numerically diagonalize the Hamiltonian (1) with N 1 = N 2 = 40.…”

“…With the basic interaction form V (r) = (α+βF·F)δ(r), the properties of such a three-component spinor condensate [4] have been demonstrated experimentally [5] and two different phases reflecting fundamental properties of spin correlation are identified: the so-called polar and ferromagnetic states for β > 0 ( 23 Na) and β < 0 ( 87 Rb) atomic condensates respectively. The mixture of two spinor condensate with the ferromagnetic and polar atoms, respectively, show more attractive quantum effects [6][7][8][9][10][11][12][13][14][15]. With the help of sympathetic cooling, the BEC mixtures of Na and Rb have been realized and it is interesting to observe the interspecies interaction induced immiscibility between the two condensates [15].…”