相关论文: Interacting double dark resonances in a hot atomic…
We study coherence effects in an atom having three metastable levels and single life-time broadened upper state. Two laser fields couple ground states to an excited one and an radio-frequency (rf) field operates between ground state levels.…
We present an investigation on the resonances of a doubly excited helium atom in a strong magnetic field covering the regime B = 0-100 a.u. A full-interaction approach which is based on an anisotropic Gaussian basis set of one-particle…
Collisions between tightly confined atoms can lead to ionization and hence to loss of atoms from the trap. We develop second-order perturbation theory for a tensorial perturbation of a spherically symmetric system and the theory is then…
The method for observing the high-contrast and narrow-width resonances of electromagnetically induced absorption (EIA) in the Hanle configuration under counterpropagating light waves is proposed. We theoretically analyze the absorption of a…
The interaction between electromagnetic microwaves (40-200 GHz) and superfluid helium in a stationary electric field has been investigated experimentally. It is found that the narrow line of resonance absorption at the roton frequency is…
Dark modes represent a class of forbidden transitions or transitions with weak dipole moments between energy states. Due to their low transition probability, it is difficult to realize their interaction with light, let alone achieve the…
Terahertz time domain spectroscopy and rigorous simulations are used to probe the coupling between a dark and a bright plasmonic eigenmode in a metamaterial with broken symmetry. The metamaterial consists of two closely spaced split ring…
Detecting coherent phonons pose different challenges compared to coherent photons due to the much stronger interaction between phonons and matter. This is especially true for high frequency heat carrying phonons, which are intrinsic lattice…
We experimentally demonstrate coherent amplification of probe field in a tripod-type atoms driven by strong coupling, signal and weak probe fields. We suppress linear and nonlinear atomic absorptions for resonant and near resonant probe via…
Enhanced sensitivity in electromagnetically induced transparency (EIT) can be obtained by the use of noise correlation spectroscopy between the fields involved in the process. Here, we investigate EIT in a cold ($< 1$ mK) rubidium vapor and…
Helium atoms in the metastable $2^3{S_{1}}$ state (He$^*$) have unique advantages for ultracold atomic experiments. However, there is no known accessible Feshbach resonance in He$^*$, which could be used to manipulate the scattering length…
We present a new measurement of the s-wave scattering length a of spin-polarized helium atoms in the 2^3S_1 metastable state. Using two-photon photoassociation spectroscopy and dark resonances we measure the energy E_{v=14}= -91.35 +/- 0.06…
We report the phenomena of electromagnetically induced transparency (EIT) and electromagnetically induced absorption (EIA) using two identical beams in rubidium atomic vapor. The {\Lambda}-type EIT configuration is employed to examine the…
Ultrarelativistic heavy ion beams carry large electromagnetic and strong absorptive fields, allowing exploration of a variety of physics. Two-photon, photon-Pomeron, and double Pomeron interactions can probe a huge variety of couplings and…
In this paper, we report on achieving hybridization effect in a Mie-based dielectric metamolecule and provide their physically intuitive picture. The hybridization results in the splitting of the initial overlapping resonance dips, thus…
We implement double electromagnetically-induced transparency (double EIT) in rubidium vapor, using a tripod-shaped energy level scheme consisting of hyperfine and magnetic sublevels of the 5S1/2 to 5P1/2 transition. We show experimentally…
We demonstrate---experimentally and theoretically---that resonances obtained in electromagnetically induced transparency (EIT) can be both bright and dark. The experiments are done using magnetic sublevels of a hyperfine transition in the…
We reinterpret the results of the direct searches for dark matter in terms of composite dark matter, i.e. dark matter particles that form neutral bound states, generically called dark atoms, either with ordinary particles, or with other…
The structure of the excited $2^{3}$S and $2^{3}$P triplet states of $^{3}$He and $^{4}$He in an applied magnetic field B is studied using different approximations of the atomic Hamiltonian. All optical transitions (line positions and…
Single, rf-trapped ions find various applications ranging from metrology to quantum computation. High-resolution interrogation of an extremely weak transition under best observation conditions requires an ion almost at rest. To avoid…