p-Wave Feshbach molecules

We have produced and detected molecules using a p-wave Feshbach resonance between 40K atoms. We have measured the binding energy and lifetime for these molecules and we find that the binding energy scales approximately linearly with the magnetic field near the resonance. The lifetime of bound p-wave molecules is measured to be 1.0+/-0.1 ms and 2.3+/-0.2 ms for the ml=+/-1 and ml=0 angular momentum projections, respectively. At magnetic fields above the resonance, we detect quasibound molecules whose lifetime is set by the tunneling rate through the centrifugal barrier.     

Evolution of the normal state of a strongly interacting Fermi gas from a pseudogap phase to a molecular Bose gas

Wave-vector resolved radio frequency spectroscopy data for an ultracold trapped Fermi gas are reported for several couplings at T(c), and extensively analyzed in terms of a pairing-fluctuation theory. We map the evolution of a strongly interacting Fermi gas from the pseudogap phase into a fully gapped molecular Bose gas as a function of the interaction strength, which is marked by a rapid disappearance of a remnant Fermi surface in the single-particle dispersion. We also show that our theory of a pseudogap phase is consistent with a recent experimental observation as well as with quantum Monte Carlo data of thermodynamic quantities of a unitary Fermi gas above T(c).     

Passive mode locking of a Nd：YAG laser with co－doped Nd, Cr：YAG as saturable absorber

We demonstrate the characteristics of relatively low saturation intensity using co-doped Nd, Cr:YAG as saturable absorber for passively mode locking the Nd:YAG laser. The difference of the saturation intensity between Q-switched and mode-locked operation in co-doped Nd, Cr:YAG was only one to two orders of magnitude, while Cr:YAG was generally reported at a difference of five orders of magnitude. More than 80% mode locking modulation depth was achieved at an incident pump power of 4.4W, corresponding to an intracavity intensity of 6×10^4W/cm^2, using a 68cm long plano-concave cavity.     

Diode-pumped self-Q-switched single-frequency 946-nm Nd(3+), Cr(4+):YAG microchip laser

A stable low-threshold self-Q-switched diode-pumped 946-nm Nd(3+), Cr(4+):YAG microchip laser operating in single frequency and fundamental transverse mode is reported. The output characteristics of the microchip laser were investigated under cw and pulsed pumping. By combination of the infrared microchip and an external frequency doubler, 473-nm pulses with a conversion efficiency of 18% were achieved.     

Ensemble Steering, Weak Self-Duality, and the Structure of Probabilistic Theories

In any probabilistic theory, we say that a bipartite state ω on a composite system AB steers its marginal state ω ^B if, for any decomposition of ω ^B as a mixture ω ^B =∑ _i p _i β _i of states β _i on B, there exists an observable {a _i } on A such that the conditional states $\omega_{B|a_{i}}$ are exactly the states β _i . This is always so for pure bipartite states in quantum mechanics, a fact first observed by Schrödinger in 1935. Here, we show that, for weakly self-dual state spaces (those isomorphic, but perhaps not canonically isomorphic, to their dual spaces), the assumption that every state of a system A is steered by some bipartite state of a composite AA consisting of two copies of A, amounts to the homogeneity of the state cone. If the state space is actually self-dual, and not just weakly so, this implies (via the Koecher-Vinberg Theorem) that it is the self-adjoint part of a formally real Jordan algebra, and hence, quite close to being quantum mechanical.     

Cr4+：YAG被动调Q激光器中受激粒子上转换效应对脉冲的影响研究

分析和报道了受激粒子能量上转换(ETU)效应对Cr:YAG 被动调Q Nd:YAG/Nd:YVO₄激光器的输出脉冲影响研究.结合ETU理论分析和被动调Q速率方程组，得到了初始反转粒子密度，末态反转粒子密度和光强最大时反转粒子密度的比值变化对激光输出脉冲宽度和脉冲能量的影响，和实验结果相一致.同时讨论了降低ETU效应的方法，有助于这类被动调Q激光器的优化设计. 关键词： 受激粒子能量上转换 Cr:YAG饱和吸收体 被动调Q