scholarly journals Polariton Induced Conical Intersection and Berry Phase

2021 ◽  
Author(s):  
Marwa Farag ◽  
Arkajit Mandal ◽  
Pengfei Huo
Keyword(s):  
Population Dynamics ◽  
Angular Distribution ◽  
Geometric Phase ◽  
Quantum Dynamics ◽  
Berry Phase ◽  
Optical Cavity ◽  
The Other ◽  
Conical Intersection ◽  
Fragment Angular Distribution ◽  
Molecular Rotations

We investigate the Polariton induced conical intersection (PICI) created from coupling a diatomicmolecule with the quantized photon mode inside an optical cavity, and the corresponding BerryPhase effects. We use the rigorous Pauli-Fierz Hamiltonian to describe the quantum light-matterinteractions between a LiF molecule and the cavity, and exact quantum propagation to investigatethe polariton quantum dynamics. The molecular rotations relative to the cavity polarization directionplay a role as the tuning mode of the PICI, resulting in an effective CI even within a diatomic molecule.To clearly demonstrate the dynamical effects of the Berry phase, we construct two additional modelsthat have the same Born-Oppenheimer surface, but the effects of the geometric phase are removed.We find that when the initial wavefunction is placed in the lower polaritonic surface, the Berryphase causes aπphase-shift in the wavefunction after the encirclement around the CI, indicatedfrom the nuclear probability distribution. On the other hand, when the initial wavefunction is placedin the upper polaritonic surface, the geometric phase significantly influences the couplings betweenpolaritonic states and therefore, the population dynamics between them. These BP effects are furtherdemonstrated through the photo-fragment angular distribution. PICI created from the quantizedradiation field has the promise to open up new possibilities to modulate photochemical reactivities.

scholarly journals Polariton Induced Conical Intersection and Berry Phase

2021 ◽  
Author(s):  
Marwa Farag ◽  
Arkajit Mandal ◽  
Pengfei Huo
Keyword(s):  
Population Dynamics ◽  
Angular Distribution ◽  
Geometric Phase ◽  
Quantum Dynamics ◽  
Berry Phase ◽  
Optical Cavity ◽  
The Other ◽  
Conical Intersection ◽  
Fragment Angular Distribution ◽  
Molecular Rotations

We investigate the Polariton induced conical intersection (PICI) created from coupling a diatomicmolecule with the quantized photon mode inside an optical cavity, and the corresponding BerryPhase effects. We use the rigorous Pauli-Fierz Hamiltonian to describe the quantum light-matterinteractions between a LiF molecule and the cavity, and exact quantum propagation to investigatethe polariton quantum dynamics. The molecular rotations relative to the cavity polarization directionplay a role as the tuning mode of the PICI, resulting in an effective CI even within a diatomic molecule.To clearly demonstrate the dynamical effects of the Berry phase, we construct two additional modelsthat have the same Born-Oppenheimer surface, but the effects of the geometric phase are removed.We find that when the initial wavefunction is placed in the lower polaritonic surface, the Berryphase causes aπphase-shift in the wavefunction after the encirclement around the CI, indicatedfrom the nuclear probability distribution. On the other hand, when the initial wavefunction is placedin the upper polaritonic surface, the geometric phase significantly influences the couplings betweenpolaritonic states and therefore, the population dynamics between them. These BP effects are furtherdemonstrated through the photo-fragment angular distribution. PICI created from the quantizedradiation field has the promise to open up new possibilities to modulate photochemical reactivities.

Geometric phase of two-qubit system in dephasing environment

2015 ◽  
Vol 29 (32) ◽  
pp. 1550236 ◽  
Author(s):  
Xiaoya Cai ◽  
Hui Pan ◽  
Z. S. Wang
Keyword(s):  
Phase Change ◽  
Quantum Computation ◽  
Geometric Phase ◽  
Berry Phase ◽  
Initial Conditions ◽  
The Other ◽  
Time Dependent ◽  
Pancharatnam Phase ◽  
Coupling System ◽  
Qubit System

We investigated the geometric phase for interaction between superconducting two-qubit system in dephased environment. The Pancharatnam phase and the Berry phase are studied. Numerical results are discussed. By considering the differently initial conditions, we find that the time-dependent Pancharatnam phase keeps the initial entangling message. On the other hand, the transition of Pancharatnam phase is dependent of the phase change in the superconducting two-qubit coupling system. Our results may be helpful to implement the time-dependent geometric quantum computation.

Polariton Induced Conical Intersection and Berry Phase

2021 ◽  
Author(s):  
Marwa H Farag ◽  
Arkajit Mandal ◽  
Pengfei Huo
Keyword(s):  
Diatomic Molecule ◽  
Berry Phase ◽  
Optical Cavity ◽  
Conical Intersection ◽  
Photon Mode

We investigate the Polariton induced conical intersection (PICI) created from coupling a diatomic molecule with the quantized photon mode inside an optical cavity, and the corresponding Berry Phase effects. We...

scholarly journals The influence of two wildfires and biological control agents on the population dynamics of Melaleuca quinquenervia in a seasonally inundated wetland

2021 ◽  
Vol 14 (1) ◽  
pp. 3-8
Author(s):  
Philip W. Tipping ◽  
Melissa R. Martin ◽  
Jeremiah R. Foley ◽  
Ryan M. Pierce ◽  
Lyn A. Gettys
Keyword(s):  
Biological Control ◽  
Population Dynamics ◽  
Seedling Recruitment ◽  
Additional Treatment ◽  
Seed Rain ◽  
The Other ◽  
Melaleuca Quinquenervia ◽  
Biological Control Agents ◽  
Seedling Mortality ◽  
Sapling Growth

AbstractThe potential of Melaleuca quinquenervia (Cav.) S.T. Blake to reinvade cleared areas was evaluated over a 13-yr period that included two wildfires and the introduction of biological control agents. The first wildfire occurred in 1998 and was followed by a mean of 591.5 recruited seedlings m−2. Recruits from that fire were cleared 7 yr later in July 2005 for a second experiment to evaluate seedling recruitment into cleared areas. Seed rain, seedling recruitment and mortality, and sapling growth rates were measured in four plots located around individual large reproductive trees. A second natural wildfire in 2007 burned through those plots, leading to increases in seed rain followed by a pulse in recruitment of 21.04 seedlings m−2, 96.5% fewer than after the 1998 fire. Recruits in half of the plots around each tree were then treated with regular applications of an insecticide to restrict herbivory by biological control agents, while herbivory was not restricted in the other half. There was no difference in seedling mortality between treatments 1,083 d post-fire (2007) with 96.6% seedling mortality in the unrestricted herbivory treatment and 89.4% mortality in the restricted herbivory treatment. Recruits subjected to the restricted herbivory treatment grew taller than those in the unrestricted herbivory treatment, 101.3 cm versus 37.4 cm. Many of the recruits were attacked by the biological control agents, which slowed their growth. Although solitary M. quinquenervia trees retain some capacity to reinvade areas under specific circumstances, there was a downward trend in their overall invasiveness at this site, with progressively smaller recruitment cohorts due to biological control agents. Land managers should prioritize removing large reproductive trees over treating recently recruited populations, which can be left for many years for the biological control agents to suppress before any additional treatment would be needed.

High-Resolution Neutron Spectroscopy for the Investigation of Hydrogen Diffusion and Molecular Rotations in Solids

1993 ◽  
Vol 48 (1-2) ◽  
pp. 406-414
Author(s):  
T. Springer
Keyword(s):  
High Resolution ◽  
Hydrogen Diffusion ◽  
Quantum Effects ◽  
Quantum States ◽  
The Other ◽  
Neutron Spectroscopy ◽  
Impurity Atoms ◽  
Molecular Rotations ◽  
Rotational Motions ◽  
Diffusion Of Hydrogen

Abstract An introductory survey on applications of high-resolution neutron spectroscopy is presented, dealing with the motion of hydrogen in solids, namely concerning (i) random rotational motions or stationary tunneling states of NH+4-ions or CH3-groups, and (ii) diffusion of hydrogen in alloys. For the rotation of hydrogenous groups in solids, at higher temperatures rotational jumps can be found, whereas quantum states are observed by μeV-spectroscopy at temperatures below 50 K. On the other hand, hydrogen diffusion does not reveal pronounced evidence of quantum effects, except for hydrogen in a metal containing impurity atoms.

Quantum dynamics of a model system with a conical intersection

1997 ◽  
Vol 106 (3) ◽  
pp. 934-941 ◽  
Author(s):  
Alessandro Ferretti ◽  
Alessandro Lami ◽  
Giovanni Villani
Keyword(s):  
Quantum Dynamics ◽  
Model System ◽  
Conical Intersection

Quantum dynamics of the photostability of pyrazine

2015 ◽  
Vol 17 (44) ◽  
pp. 29518-29530 ◽  
Author(s):  
Matthieu Sala ◽  
Stéphane Guérin ◽  
Fabien Gatti
Keyword(s):  
Electronic State ◽  
Ground State ◽  
Quantum Dynamics ◽  
Ground Electronic State ◽  
Conical Intersection ◽  
Radiationless Decay

We propose a new mechanism for the radiationless decay of photoexcited pyrazine to its ground electronic state involving a conical intersection between the dark Au(nπ) state and the ground state.

The population dynamics of metacercariae of Apatemon gracilis (Trematoda: Digenea) in three species of lake-dwelling leeches

Parasitology ◽  
1986 ◽  
Vol 93 (3) ◽  
pp. 517-530 ◽  
Author(s):  
S. M. Spelling ◽  
J. O. Young
Keyword(s):  
Population Dynamics ◽  
Relative Density ◽  
Sexual Maturity ◽  
Egg Production ◽  
Seasonal Pattern ◽  
Distinct Pattern ◽  
The Other ◽  
Mean Intensity ◽  
Density Values ◽  
Host Mortality

SUMMARYMonthly samples of the leeches Erpobdella octoculata, Glossiphonia complanata and Helobdella stagnalis were taken over a two-year period from an eutrophic, English lake to detect metacercariae of the trematode, Apatemon gracilis. In each cohort of each of the three leeches, prevalence was low in young individuals, rose to a peak in autumn/winter, and then declined until the cohort had almost died out; in E. octoculata and H. stagnalis a final brief increase occurred. Mean intensity and relative density values followed a similar seasonal pattern of change to that of prevalence in these last two species, but in G. complanata values fluctuated irregularly with no distinct pattern. The frequency distribution of the parasite in G. complanata was highly over-dispersed, but less so in the other two species. Infected E. octoculata reached sexual maturity. The parasite reduced egg production in G. complanata and H. stagnalis, but only by maximum values of 2·5 and 9% respectively. This reduction in fecundity is low compared to the subsequent high mortality, at 95% or more, of newly recruited young from as yet unidentified causes. Parasite-related host mortality was difficult to assess in young leeches, but there was some evidence for its occurrence in older leeches of E. octoculata and H. stagnalis. However, this is unlikely to play a prominent role in the control and regulation of lacustrine leech populations.

Fission fragment angular distribution for theF19+Au197fusion-fission reaction at near-barrier energies

2005 ◽  
Vol 71 (4) ◽  
Author(s):  
R. Tripathi ◽  
K. Sudarshan ◽  
S. Sodaye ◽  
A. V. R. Reddy ◽  
K. Mahata ◽  
...  
Keyword(s):  
Angular Distribution ◽  
Fission Fragment ◽  
Fission Reaction ◽  
Fragment Angular Distribution

scholarly journals How Quickly are Road-killed Snakes Scavenged? Implications for Underestimates of Road Mortality

2011 ◽  
Vol 127 (2) ◽  
pp. 184-188 ◽  
Author(s):  
BRETT A. DEGREGORIO ◽  
THOMAS E. HANCOCK ◽  
DAVID J. KURZ ◽  
SAM YUE
Keyword(s):  
United States ◽  
Population Dynamics ◽  
Community Composition ◽  
The United States ◽  
The Other ◽  
Road Mortality ◽  
Correction Factors ◽  
Significant Extent ◽  
Removal Time ◽  
Maritime Forest

Abstract Annually, millions of snakes are killed on roads in the United States. Because of their potential abundance and ease of collection, many researchers have used road-killed snakes to examine community composition, movement patterns, and population dynamics. However, few previous studies have accounted for snake carcasses that are removed from roads by scavengers. Snake carcasses were placed at randomly selected locations along 2 km of road, one traversing maritime forest and the other surrounded by dune habitat. Carcasses in forested habitat were removed more often (100% vs 40%) and more quickly (8 hr vs 11 hr) than those placed in dune habitat. Half of the carcasses (50%) were removed within eight hours of placement and all carcasses were removed at night. Species and size of carcasses did not affect removal time. Removal time and scavenging intensity of snake carcasses most likely varies across regions and habitats. Furthermore, because scavenging appears to occur quickly and to such a significant extent, it may confound results of studies examining patterns of road-mortality. Thus, investigators that use data from road-killed snakes would benefit from a concurrent investigation of scavenging and application of appropriate correction factors to avoid underestimation of snake mortality.

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