Beamsplitters have played an important role in quantum optics experiments. They are often used to split and combine two beams, especially in the construct of an interferometer. In this letter, we experimentally implement a nonlinear beamsplitter using a phase-sensitive parametric amplifier, which is based on four-wave mixing in hot rubidium vapor. Here we show that, despite the differentfrequencie...

Electron–ion coincidence detection allows one to visualize the ultrafast chemical reactions of molecules in strong laser fields. Here, by measuring the photoelectron angular distribution (PAD) of H2 in strong laser fields correlated to different pathways, i.e., direct ionization when the internuclear distance is small, or ionization after the molecular bond stretches to a large internuclear distan...

Scale invariance plays an important role in unitary Fermi gases. Discrete scaling symmetry manifests itself in quantum few-body systems such as the Efimov effect. Here, we report on the theoretical prediction and experimental observation of a distinct type of expansion dynamics for scale-invariant quantum gases.When the frequency of the harmonic trap holding the gas decreases continuously as the i...

We present a physical setup for realizing all-real-spectrum optical potentials with arbitrary gain-and-loss distributions in a coherent medium consisting of a cold three-level atomic gas driven by control and probe laser fields. We show that by the interference of Raman resonances and the Stark shift induced by a far-detuned laser field, tunable, non-parity-time (non-PT )-symmetric optical potenti...