Export 60 results:
Sort by: Author [ Title  (Desc)] Type Year
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 
Hsiao, Y-F, Lin Y-J, Chen Y-C.  2018.  Λ -enhanced gray-molasses cooling of cesium atoms on the D 2 line. Phys. Rev. A. 98(033419)
Kim, B, Chen K-T, Hsiao S-S, Wang S-Y, Li K-B, Ruseckas J, Juzeliūnas G, Kirova T, Auzinsh M, Chen Y-C, Chen Y-F, Yu IA.  2021.  A weakly-interacting many-body system of Rydberg polaritons based on electromagnetically in-duced transparency. Commun. Phys. 4:101(2021)
Simien, CE, Chen YC, Gupta P, Laha S, Martinez YN, Mickelson PG, Nagel SB, Killian TC.  2004.  Using absorption imaging to study ion dynamics in an ultracold neutral plasma, Apr. Physical Review Letters. 92:4., Number 14 AbstractWebsite

We report optical absorption imaging of ultracold neutral strontium plasmas. The ion absorption spectrum determined from the images is Doppler broadened and thus provides a quantitative measure of the ion kinetic energy. For the particular plasma conditions studied, ions heat rapidly as they equilibrate during the first 250 ns after plasma formation. Equilibration leaves ions on the border between the weakly coupled gaseous and strongly coupled liquid states. On a longer time scale of microseconds, pressure exerted by the trapped electron gas accelerates the ions radially.

Lin, YW, Chou HC, Dwivedi PP, Chen YC, Yu IA.  2008.  Using a pair of rectangular coils in the MOT for the production of cold atom clouds with large optical density, Mar. Optics Express. 16:3753-3761., Number 6 AbstractWebsite

We demonstrate a simple method to increase the optical density (OD) of cold atom clouds produced by a magneto-optical trap (MOT). A pair of rectangular anti-Helmholtz coils is used in the MOT to generate the magnetic field that produces the cigar-shaped atom cloud. With 7.2 x 10(8) Rb-87 atoms in the cigar-type MOT, we achieve an OD of 32 as determined by the slow light measurement and this OD is large enough such that the atom cloud can almost contain the entire Gaussian light pulse. Compared to the conventional MOT under the same trapping conditions, the OD is increased by about 2.7 folds by this simple method. In another MOT setup of the cigar-shaped Cs atom cloud, we achieve an OD of 105 as determined by the absorption spectrum of the |6S(1/2), F = 4 > ->| 6P(3/2), F ' = 5 > transition. (C) 2008 Optical Society of America

Killian, TC, Chen YC, Gupta P, Laha S, Martinez YN, Mickelson PG, Nagel SB, Saenz AD, Simien CE.  2005.  Ultracold neutral plasmas, May. Plasma Physics and Controlled Fusion. 47:A297-A306. AbstractWebsite

Ultracold neutral plasmas are formed by photo-ionizing laser-cooled atoms near the ionization threshold. Through the application of atomic physics techniques and diagnostics, these experiments stretch the boundaries of traditional neutral plasma physics. The electron temperature in these plasmas ranges from 1 to 1000 K and the ion temperature is around 1 K. The density can approach 10(11) cm(-3). Fundamental interest stems from the possibility of creating strongly coupled plasmas, but recombination, collective modes, and thermalization in these systems have also been studied. Optical absorption images of a strontium plasma, using the Sr+ S-2(1/2) -> P-2(1/2) transition at 422 mn, depict the density profile of the plasma, and probe kinetics on a 50 ns time-scale. The Doppler-broadened ion absorption spectrum measures the ion velocity distribution, which gives an accurate measure of the ion dynamics in the first microsecond after photo-ionization.

Tsai, P-J, Chen Y-C.  2018.  Ultrabright, narrow-band photon-pair source for atomic quantum memories. Quantum Sci. Technol. 3 (034005)
Tsai, P-J, Wei Y-C, Wu B-H, Li S-X, Chen Y-C.  2020.  Theoretical study on memory-based optical converter with degenerate Zeeman states. Phys. Rev. A. 100(063843)Link
Wang, Y-S, Li K-B, Chang C-F, Lin T-W, Li J-Q, Hsiao S-S, Chen J-M, Lai Y-H, Chen Y-C, Chen Y-F, Chuu C-S, Yu IA.  2022.  Temporally ultralong biphotons with a linewidth of 50 kHz.. APL Photonics. 7(12), 126102(2022)
Jen, HH, Chang M-S, Lin G-D, Chen Y-C.  2019.  Subradiance dynamics in a singly-excited chiral-coupled atomic chain. arXiv:1905.00558.
Jen, HH, Chang M-S, Lin G-D, Chen YC.  2020.  Subradiance dynamics in a singly excited chirally coupled atomic chain. PHYSICAL REVIEW A. 101(023830)Link
Mickelson, PG, Martinez YN, Saenz AD, Nagel SB, Chen YC, Killian TC, Pellegrini P, Cote R.  2005.  Spectroscopic determination of the s-wave scattering lengths of Sr-86 and Sr-88, Nov 25. Physical Review Letters. 95 AbstractWebsite

We report the use of photoassociative spectroscopy to determine the ground-state s-wave scattering lengths for the main bosonic isotopes of strontium, Sr-86 and Sr-88. Photoassociative transitions are driven with a laser red detuned by up to 1400 GHz from the S-1(0)-P-1(1) atomic resonance at 461 nm. A minimum in the transition amplitude for Sr-86 at -494 +/- 5 GHz allows us to determine the scattering lengths 610a(0)< a(86)< 2300a(0) for Sr-86 and a much smaller value of -1a(0)< a(88)< 13a(0) for Sr-88.

Jen, HH, Chen YC.  2016.  Spectral shaping of cascade emissions from multiplexed cold atomic ensembles. Physical Review A. 93 :013811.
Chen, YC, Liao YA, Hsu L, Yu IA.  2001.  Simple technique for directly and accurately measuring the number of atoms in a magneto-optical trap, Sep. Physical Review A. 64 AbstractWebsite

We have systematically studied a simple technique that accurately determines number of atoms in a magneto-optical trap, Absorption energy of a laser field that interacts with cold atoms is a direct measurement of atom number. The measured energy neither depends on the detuning, intensity, and polarization of the laser field nor is affected by other system parameters. Our work also demonstrates that such technique can be applied to study the phenomenon of coherent population trapping.

Chen, J-M, Hsu C-Y, Huang W-K, Hsiao S-S, Huang F-C, Chen Y-H, Chuu C-S, Chen Y-C, Chen Y-F, Yu IA.  2022.  Room-temperature biphoton source with a spectral brightness near the ultimate limit.. Physical Review Research. 4, 023132(2022)
Chen, J-M, Hsu C-Y, Huang W-K, Hsiao S-S, Huang F-C, Chen Y-H, Chuu C-S, Chen Y-C, Chen Y-F, Yu IA.  2022.  Room-temperature biphoton source with a spectral brightness near the ultimate limit. Phys. Rev. Research. 4, 023132(2022)
Chen, YC, Lin CW, Yu IA.  2000.  Role of degenerate Zeeman levels in electromagnetically induced transparency, May. Physical Review A. 61:6., Number 5 AbstractWebsite

We have observed various Lambda-type electromagnetically induced transparency (EIT) spectra in laser-cooled Rb-87 atoms of different laser polarization configurations. Unexpected profiles occur in the EIT spectra. We have found the degenerate Zeeman sublevels are responsible for these profiles. The experimental data are in good agreement with the results from the theoretical calculation which takes into account all the 13 Zeeman levels in the Lambda system. Our study demonstrates that Zeeman sublevels play important roles in quantum interference phenomena such as EIT and amplification without population inversion (AWI), and should be taken into account in the analysis of these phenomena.

Jen, HH, Lin G-D, Chen Y-C.  2022.  Resonant dipole-dipole interactions in electromagnetically induced transparency.. PHYSICAL REVIEW A. 105, 063711(2022)
Jen, H-H, Lin G-D, Chen Y-C.  2022.  Resonant dipole-dipole interactions in electromagnetically induced transparency. Phys. Rev. A. 105, 063711(2022)
Tsai, P-J, Hsiao Y-F, Chen Y-C.  2020.  Quantum storage and manipulation of heralded single photons in atomic quantum memories. Phys. Rev. Research. 2(033155)Link
Chen, YW, Lin CW, Chen YC, Yu IA.  2002.  Quantization axes in coherent two-field spectroscopy, Aug. Journal of the Optical Society of America B-Optical Physics. 19:1917-1921., Number 8 AbstractWebsite

Coherent two-field spectroscopy calculations with different choices of the quantization (z) axis are compared. In a system driven by a strong coupling field and a weak probe field, alignment of the z axis along either the polarization direction of a linearly polarized coupling field or the propagation direction of a circularly polarized coupling field is shown to simplify the calculations and facilitate interpretation of the results. The advantages of a suitable choice of the z axis are highlighted with an example of a degenerate three-level system of electromagnetically induced transparency. (C) 2002 Optical Society of America.

Chen, YC, Chen YW, Su JJ, Huang JY, Yu IA.  2001.  Pump-probe spectroscopy of cold Rb-87 atoms in various polarization configurations, Apr. Physical Review A. 63:11., Number 4 AbstractWebsite

We investigate systematically pump-probe spectroscopy of cold Rb-87 atoms produced by a magneto-optical trap. The pump-probe spectra are measured without the presence of the trapping beams or any optical molasses. Various polarization configurations of the probe and pump fields result in very different spectra of probe absorption. The observed spectra exhibit a dispersive profile, a dispersionlike profile, a Lorentzian profile, or a dispersive profile plus a Lorentzian profile. The widths of all the spectral profiles are narrower than the natural linewidth of the excited state. Our work clarifies the mechanisms behind these different spectral profiles and provides essential information for the pump-probe spectroscopy of cold atoms.

Chan, Y-H, Jiang H-C, Chen Y-C.  2023.  Plaquette valence bond state in the spin- 12 J1 -J2 XY model on the square lattice.. PHYSICAL REVIEW B. 107, 214402(2023)
Nagel, SB, Mickelson PG, Saenz AD, Martinez YN, Chen YC, Killian TC, Pellegrini P, Cote R.  2005.  Photoassociative spectroscopy at long range in ultracold strontium, Mar 4. Physical Review Letters. 94 AbstractWebsite

We report photoassociative spectroscopy of Sr-88(2) in a magneto-optical trap operating on the S-1(0)-->P-3(1) intercombination line at 689 nm. Photoassociative transitions are driven with a laser red detuned by 600-2400 MHz from the S-1(0)-->P-1(1) atomic resonance at 461 nm. Photoassociation takes place at extremely large internuclear separation, and the photoassociative spectrum is strongly affected by relativistic retardation. A fit of the transition frequencies determines the P-1(1) atomic lifetime (tau=5.22+/-0.03 ns) and resolves a discrepancy between experiment and recent theoretical calculations.

Chen, YC, Liao YA, Chiu HY, Su JJ, Yu IA.  2001.  Observation of the quantum interference phenomenon induced by interacting dark resonances, Nov. Physical Review A. 64:5., Number 5 AbstractWebsite

We report an experimental observation of narrow and high-contrast spectra. which are induced by interacting dark resonances and have been predicted in Phys. Rev. A 60, 3225 (1999). Spectra are measured with cold (87)Rb atoms produced by a magneto-optical trap. In this experimental system, a coupling laser and a weak probe laser form a three-level Lambda -type configuration of electromagnetically induced transparency (EIT); a microwave drives a magnetic-dipole transition between the fourth level and the ground state that is coupled with the excited state by the coupling laser. The observed spectral profile of probe absorption exhibits a very sharp peak emerging inside a narrow EIT dip. Such spectral feature provides more opportunities in manipulating atomic-optical response.

Wei, Y-C, Lin S-X, Tsai P-J, Chen Y-C.  2020.  Memory-based optical polarization conversion in a double-Λ atomic system with degenerate Zeeman states. Sci Rep. 10, 13990 (2020) Link