546 research outputs found
Correlations between interacting Rydberg atoms
No full textThis paper is a short introduction to Rydberg physics and quantum nonlinear optics using Rydberg atoms. It has been prepared as a compliment to a series of lectures delivered during the Latin American School of Physics "Marcos Moshinsky" 2017. We provide a short introduction to the properties of individual Rydberg atoms and discuss in detail how the interaction potential between Rydberg atom pairs is calculated. We then discuss how this interaction gives rise to the Rydberg blockade mechanism. With the aid of hallmark experiments in the field applications of the blockade for creating correlated quantum systems are discussed. Our aim is to give an overview of this exciting and rapidly evolving field. The interested reader is referred to original work and more comprehensive reviews and tutorials for further details on these subjects.</p
Tunable quantum criticality in multicomponent Rydberg arrays
No full textArrays of Rydberg atoms have appeared as a remarkably rich playground to
study quantum phase transitions in one dimension. One of the biggest puzzles
that was brought forward in this context are chiral phase transitions out of
density waves. Theoretically predicted chiral transition out of period-four
phase is still pending experimental verification mainly due to extremely short
interval over which this transition is realized in a single-component Rydberg
array. In this letter we show that multi-component Rydberg arrays with extra
experimentally tunable parameters provide a mechanism to manipulate quantum
critical properties without breaking translation symmetry explicitly.
We consider an effective blockade model of two component Rydberg atoms. Weak
and strong components obey nearest- and next-nearest-neighbor blockades
correspondingly. When laser detuning is applied to either of the two components
the system is in the period-3 and period-2 phases. But laser detuning applied
to both components simultaneously stabilizes the period-4 phase partly bounded
by the chiral transition. We show that relative ratio of the Rabi frequencies
of the two components tunes the properties of the conformal Ashkin-Teller point
and allows to manipulate an extent of the chiral transition. The prospects of
multi-component Rydberg arrays in the context of critical fusion is briefly
discussed.Comment: 11 pages, 14 figure
RYDBERG SERIES IN SMALL MOLECULES
No full textAuthor Institution: Physics Department, The Royal Institute of TechnologyA qualitative discussion of the Rydberg series of a diatomic molecule, consisting of atoms such as C, N, O, shows that the quantum defect is approximately independent of the nature of the molecule, and depends only on the type of the Rydberg orbital. It is shown that the orbitals and probably have different quantum defects and that has a much larger quantum defect than and . The systematics has been applied to , and and a number of new Rydberg series have been found and others have been reinterpreted
THE RYDBERG STATES OF NO.
No full textThis work was supported by NASA Grant NsG-414.Author Institution: Department of Astrophysical Sciences, Princeton UniversityThe interpretation of the lowest Rydberg states of NO given recently by Huber and has been fully confirmed by the identification in the absorption spectrum, of several higher members of the proposed Rydberg The exceedingly complex spectrum can now be interpreted, owing to the work of Miescher and his in terms of a relatively simple electronic energy level diagram. The pattern of Rydberg states resembles strongly that of an atom with closed-shell core. The molecular states corresponding to atomic p- and d- states split into components with different , but in NO the sign of this splitting is opposite to the one expected and found in Rydberg states of , and CO. The pattern observed in NO has been reproduced rather well in the recent theoretical calculation by LeFebvre-Brion and who have taken into account the configuration interaction between the unoccupied (Rydberg-) orbitals though they have not included the interaction with excited valence-shell configurations. The relative absorption intensities of the Rydberg bands and the interactions with non-Rydberg states are well explained by the assignment of approximate and symmetries to the states of the nearly symmetric NO molecule. The type Rydberg states of configurations and appear with much greater absorption intensities than those resembling atomic and states and they interact strongly with the non-Rydberg states and with the repulsive state . These and other observations confirm that it is meaningful to describe the lowest Rydberg states of NO with quantum numbers 3s, 3p, 3d of an atom with a closed -shell core such as Boron or Sodium
COOPERATIVE EFFECTS IN A RYDBERG GAS
No full textAuthor Institution: Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02319Rydberg-Rydberg transitions of Ca atoms are directly detected by chirped-pulse millimeter-wave spectroscopy with broadband, high-resolution spectra with accurate relative intensities. At moderate high number density, the radiation of a Rydberg gas behaves as strong cooperative effects. Compared to a rotational transition, Rydberg-Rydberg transitions have enormous electric dipole transition moments and polarizabilities, which are sensitive to external and self-induced electric fields. In a dense Rydberg gas, a large group of molecules can share an electric field, and absorb and radiate cooperatively. A model with semiclassical method describes several significant cooperative effects in the time-domain and frequency-domain in two-level systems and -type three-level systems. Several experimental evidences which partly support this model will be discussed and a new experiment with buffer gas cooling technique will be proposed
MILLIMETER WAVE SPECTROSCOPY OF HIGH RYDBERG STATES OF Kr
No full textAuthor Institution: ETH Z\""{u}rich, Laboratorium f\""{u}r Physikalische Chemie, ETH-H\""{o}nggerberg HClA phase-stabilized backward wave oscillator (BWO) in the GHz range was combined with an XUV laser system to record high-resolution spectra of high Rydberg states of krypton. The millimeter wave transitions between high n Rydberg states were detected by pulsed field-ionization, at sub-MHz resolution. Results are presented on the hyperfine structure of high n Rydberg states of
RYDBERG STATES OF POLYATOMIC FREE RADICALS
No full textAuthor Institution: Purdue University, West LafayetteOpen Shell acyl free radical produce closed shell cations that support sharp Rydberg states. Ion-detected absorption shows extensive structure in HCO and . Presented here are the first resolved spectra of obtained by (1+1) double-resonant photoionization. These states are analyzed and used as intermediate to probe higher level Rydberg states near the ionization threshold
HIGH-RYDBERG AND AUTOIONIZING STATES OF HCO
No full textAuthor Institution: Purdue University, West Lafayette, IN 47906Double-resonant transitions through the Rydberg state of HCO state-select autoionizing series converging to specific vibrationally excited thresholds of . Extrapolation of series, combined with exisiting knowledge of the vibrational structure of the cation, provides the first accurate determination of the adiabatic ionization potential of HCO, Lineshapes and intensities of resonances reflect mode-specific trends in Rydberg-core coupling dynamics
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Ultracold Rydberg Atoms
No full textThis thesis presents a new experimental facility that has been developed in the course of the PhD of the author together with the experimental measurements of the dipole moments for transitions between 5P3/2 and nD5/2 states in Rb atoms, where 20 ≤ n ≤ 48. A laser cooling setup for rubidium atoms was designed and built that allows to produce 3 x 10 atoms at temperature of few microkelvins. A laser system for coherent excitation to Rydberg states was realised that exploits a two-photon ladder excitation scheme. Such setup allowed to directly measure transition dipole moments from the first excited state to high n Rydberg states. The electromagnetically induced transparency and Autler-Townes splitting phenomena were exploited in order to obtain the values of the dipole moments, which were found to be in an excellent agreement with the theoretical values calculated using the quasiclassical approach by our collaborators in Novosibirsk. To the author's knowledge, these are the first direct measurements of such dipole moments. The data shown in the thesis proves the reliability of the measurement method. The obtained results are extremely useful to validate theoretical models and gain insight in the physics of the interactions that will be an object of subsequent studies. The methods presented in the dissertation will be used in the future to detect in a non-destructive way Rydberg-Rydberg interactions within mesoscopic samples
RYDBERG STATES: STEALTHY SPIES OF MOLECULAR STRUCTURE
No full textAuthor Institution: Department of Chemistry, Brown University, Providence R.I., 02912Electrons in Rydberg orbits are sensitive spies of molecular structure. Typically, the motions of flexible hydrocarbon chains are famously difficult to observe. Large amplitude vibrations born from high internal temperatures where the molecules vibrate in soft potentials blur the conformeric snapshot. We explore the equilibrium composition and dynamics between conformeric structures of ,-dimethyl-2-butanamine (DM2BA) and ,-dimethyl-3-hexanamine (DM3HA) using the Rydberg Fingerprint method. Initial excitation prepares the molecule in the 3 state and subsequent relaxation to 3 deposits 1.8 eV of vibrational energy, elevating the internal temperature to some 900 K. The time-dependent Rydberg spectrum reveals the conformational dynamics of the hot hydrocarbon chains, enabling us to measure time constants for both the forward and backward reactions
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