scholarly journals Stabilization of All Bell States in a Lossy Coupled-Cavity Array

Entropy ◽  
2019 ◽  
Vol 21 (4) ◽  
pp. 402
Author(s):  
Bing Liu ◽  
Dong-Xiao Li ◽  
Xiao-Qiang Shao
Keyword(s):  
Relative Phase ◽  
Singlet State ◽  
High Fidelity ◽  
Triplet States ◽  
Optical Cavities ◽  
Quantum Jump ◽  
Quantum Feedback ◽  
Maximally Entangled States ◽  
Classical Fields ◽  
Coupled Cavity

A scheme is proposed to generate maximally entangled states of two Λ -type atoms trapped in separate overdamped optical cavities using quantum-jump-based feedback. This proposal can stabilize not only the singlet state, but also the other three triplet states by alternating the detuning parameter and relative phase of the classical fields. Meanwhile it is convenient to manipulate atoms, and much more robust against spontaneous emission of atoms. The parameters related to the potential experiment are analyzed comprehensively and it is confirmed that the quantum feedback technology is a significant tool for entanglement production with a high fidelity.

The radiation-induced formation of excited states of aromatic hydrocarbons in benzene and cyclohexane, II. Yields of excited singlet and triplet state solute molecules

1972 ◽  
Vol 328 (1575) ◽  
pp. 457-479 ◽  
Keyword(s):  
Excited States ◽  
Pulse Radiolysis ◽  
Singlet State ◽  
Relative Yield ◽  
Excited Singlet State ◽  
High Yield ◽  
Triplet States ◽  
Excited Singlet ◽  
Concentration Dependences ◽  
Radiation Induced

The concentration dependences of the yield of excited triplet states, G ( 3 S*), and the concentration dependences of the relative yield of radiation-induced fluorescence obtained on pulse radiolysis of solutions of naphthalene, anthracene, pyrene and 2,5-diphenyloxazole (PPO) are reported. The yields of excited singlet state solute molecules, G ( 1 S*), formed on pulse radiolysis of naphthalene-cyclohexane and naphthalene-benzene solutions has been determined by comparing the intensity of the radiation-induced fluorescence with that obtained on photo-excitation. It is concluded that intersystem crossing (i.s.c.) from the excited singlet state is an important process in the formation of the high yield of triplet excited states of the solute. Under certain conditions this process accounts for up to 50 % of G ( 3 S*) in cyclohexane and the entire G ( 3 S*) in benzene solutions.

Molecular orbital studies of the singlet and triplet states of formylmethylene conformers

1991 ◽  
Vol 69 (11) ◽  
pp. 1630-1635 ◽  
Author(s):  
Ratnakar K. Gosavi ◽  
Manuel Torres ◽  
Otto P. Strausz
Keyword(s):  
Singlet State ◽  
Closed Shell ◽  
Basis Set ◽  
Planar Geometry ◽  
Present Calculation ◽  
Triplet States ◽  
Excited Singlet ◽  
Singlet And Triplet States ◽  
Ci Calculations ◽  
Single Configuration

The energies and geometries of the low-lying electronic states of formylmethylene have been calculated at the SCF and CI levels using 6-31G** basis set. In agreement with previous reports and accumulated experimental observations, the ground state is the carbenoid triplet with a planar geometry. Also, in agreement with all previous single configuration SCF and CI calculations, the lowest excited singlet state is computed to be the nonplanar closed shell carbenoid structure. In contrast, accumulated experimental evidence along with previously reported MC–SCF results require this state to be planar. The present calculation predicts the existence of a (σ–σ) 1,3-diradical 1A′ state, which appears to be identical to the MC–SCF lowest singlet state, but this state lies some 11 kcal/mol above the closed shell carbenoid 1A state. Apparently, single configuration SCF methods are inadequate for the correct description of the electronic manifold of formylmethylene. Key words: formylmethylene, singlet and triplet states, ab initio MO calculations, conformers, molecular structure.

scholarly journals Generation of Multicavity Entangled States with a Single Three-Level Atom

2000 ◽  
Vol 53 (6) ◽  
pp. 799 ◽  
Author(s):  
Shi-Biao Zheng
Keyword(s):  
Vacuum State ◽  
Atomic State ◽  
Entangled States ◽  
Simple Scheme ◽  
Photon State ◽  
Level Atom ◽  
Field State ◽  
Maximally Entangled States ◽  
Classical Fields

A simple scheme is proposed for the generation of maximally entangled states for several separated cavities, in which each cavity is in a one-photon state or in the vacuum state. In the scheme a laddertype three-level atom is sent through the cavities and additional classical fields. The whole system finally evolves into a state, which is given by the product of the highly entangled field state with an atomic state.

Cooling distant atoms into steady entanglement via coupled cavities

2013 ◽  
Vol 13 (3&4) ◽  
pp. 281-289
Author(s):  
Li Tuo Shen ◽  
Xin Yu Chen ◽  
Zhen-Biao Yang ◽  
Huai-Zhi Wu ◽  
Shi-Biao Zheng
Keyword(s):  
Steady State ◽  
Laser Cooling ◽  
Ground State ◽  
Entangled State ◽  
High Fidelity ◽  
Maximally Entangled State ◽  
Coupled Cavities ◽  
Laser Frequencies ◽  
Cavity System ◽  
Coupled Cavity

We propose a scheme for generating steady-state entanglement between two distant atomic qubits in the coupled-cavity system via laser cooling. With suitable choice of the laser frequencies, the target entangled state is the only ground state that is not excited by the lasers due to large detunings. The laser excitations of other ground states, together with dissipative processes, drive the system to the target state which is the unique steady state of the system. Numerical simulation shows that the maximally entangled state with high fidelity can be produced with presently available cooperativity.

scholarly journals High-fidelity measurement and quantum feedback control in circuit QED

2005 ◽  
Vol 72 (6) ◽  
Author(s):  
Mohan Sarovar ◽  
Hsi-Sheng Goan ◽  
T. P. Spiller ◽  
G. J. Milburn
Keyword(s):  
Feedback Control ◽  
High Fidelity ◽  
Circuit Qed ◽  
Quantum Feedback

DYNAMICS OF A COUPLED CAVITY SYSTEM COMPOSED OF THREE CAVITIES

2012 ◽  
Vol 10 (06) ◽  
pp. 1250070 ◽  
Author(s):  
ZHI-RONG ZHONG ◽  
XIU LIN ◽  
BIN ZHANG ◽  
ZHEN-BIAO YANG
Keyword(s):  
Theoretical Basis ◽  
Quantum States ◽  
Entangled States ◽  
W States ◽  
Atomic Excitation ◽  
Level Atom ◽  
Cavity System ◽  
Maximally Entangled States ◽  
The One ◽  
Coupled Cavity

We study the one-excitation dynamics of a coupled cavity system composed of three cavities, each containing a two-level atom. By adjusting the atom–cavity detuning Δ, cavity–cavity hopping rate v and the initial atomic excitation residential, a wide variety of time-evolution behaviors can be realized. Under certain conditions, the two-atom maximally entangled states and three-atom W states can be obtained. The results provide a theoretical basis for the manipulation of quantum states in such a system and will contribute to the understanding of more complex systems.

Low-lying activated states of chloroiridium phthalocyanine aggregates in glassy solution at low temperatures

1988 ◽  
Vol 66 (1) ◽  
pp. 86-92 ◽  
Author(s):  
W.-H. Chen ◽  
K. E. Rieckhoff ◽  
E.-M. Voigt
Keyword(s):  
Singlet State ◽  
Torsional Oscillation ◽  
Zero Point ◽  
Triplet States ◽  
Excited Singlet ◽  
Glassy Solution ◽  
Ground Singlet State ◽  
Modes Of Vibration ◽  
State Formula ◽  
Singlet And Triplet States

Studies of phosphorescence intensities and lifetimes of two chloroiridium phthalocyanine aggregates in α-chloronaphthalene between 5 and 80 K have revealed the existence of low-lying activated states only a few tens of cm−1 above the zero-point vibration in both lowest singlet and triplet states. From the data, activation energies of intersystem crossings between the two multiplicities associated with these states have been obtained as follows: for crossing from the first excited singlet to the lowest triplet state, Ea = 42 ± 10 and 29 ± 10 cm−1, respectively, for the two aggregates; for crossing from the lowest triplet to the ground singlet state, [Formula: see text] and 23 ± 5 cm−1, respectively. These activated states are tentatively attributed to certain intermolecular modes of vibration in aggregates. Specifically, they fit the model of molecular torsional oscillation of two and three parallel-sheet arrangements. On the basis of these findings, we propose that the first Ea (or [Formula: see text]) is the fundamental librational frequency of the dimer and the second Ea (or [Formula: see text]) is that for the trimer.

Deterministic multi-atom GHZ states generation in a coupled cavity system with the assistance of strong classical fields

2012 ◽  
Vol 86 (5) ◽  
pp. 055008 ◽  
Author(s):  
Zhi-Rong Zhong ◽  
Xiu Lin ◽  
Bin Zhang ◽  
Zhen-Biao Yang
Keyword(s):  
Ghz States ◽  
Cavity System ◽  
Classical Fields ◽  
Coupled Cavity

Emission and Deactivation of the Excited States of 2,3-Pentanedione

1972 ◽  
Vol 50 (9) ◽  
pp. 1338-1344 ◽  
Author(s):  
A. W. Jackson ◽  
A. J. Yarwood
Keyword(s):  
Triplet State ◽  
Gas Phase ◽  
Excited States ◽  
Singlet State ◽  
Triplet States ◽  
Excited Singlet ◽  
Vibrationally Excited ◽  
Singlet Level ◽  
Singlet And Triplet States ◽  
Fluorescence And Phosphorescence

Vibrationally excited singlet and triplet states of 2,3-pentanedione are formed by photolysis at 365 nm. The processes removing these excited states in the gas phase are studied by measuring the fluorescence and phosphorescence yields. Fluorescence can occur from the vibrationally excited, as well as the vibrationally equilibrated, singlet state. The fluorescence and phosphorescence data are considered in terms of mechanisms which involve either weak or strong collisions. Although the data cannot distinguish between the alternatives, there are two significant conclusions. The fluorescence data require that emission occur from at least two levels in the singlet manifold. To explain the phosphorescence data, the highest emitting singlet level must not lead to a vibrationally equilibrated triplet state.

Generation of Three-Atom Singlet State with High-Fidelity by Lyapunov Control

2021 ◽  
Author(s):  
Bing-Jie Li ◽  
Shuai Liu ◽  
Yu Wang ◽  
Yi-Hao Kang ◽  
Zhi-Cheng Shi ◽  
...  
Keyword(s):  
Singlet State ◽  
High Fidelity ◽  
Lyapunov Control
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