The electronic structure and spin-charge separation of one-dimensional SrCuO2

2019 ◽  
Vol 33 (02) ◽  
pp. 1950006
Author(s):  
Huaisong Zhao ◽  
Jiasheng Qian ◽  
Sheng Xu ◽  
Feng Yuan
Keyword(s):  
Electronic Structure ◽  
Charge Separation ◽  
Energy Region ◽  
Doping Concentration ◽  
High Energy ◽  
Intermediate Energy ◽  
Low Energy ◽  
One Dimensional ◽  
High Energy Peak ◽  
Energy Peak

Based on the t-J model and slave-boson theory, we have studied the electronic structure in one-dimensional SrCuO2 by calculating the electron spectrum. Our results show that the electron spectra are mainly composed of three parts in one-dimensional SrCuO2, a sharp low-energy peak, a broad intermediate-energy peak and a high-energy peak. The sharp low-energy peak corresponds to the main band (MB) while the broad intermediate-energy peak and high-energy peak are associated with the shadow band (SB) and high-energy band (HB), respectively. From low-energy to intermediate-energy region, a clear two-peak structure (MB and SB) around the momentum [Formula: see text] appears, and the distance between two peaks decreases along the momentum direction from [Formula: see text] to [Formula: see text], then disappears at the critical momentum point [Formula: see text], leaving a single peak above [Formula: see text]. The electron spectral function in one-dimensional SrCuO2 is also the doping and temperature dependent. In particular, in the very low doping concentration, the HB merges into the MB. However, with the increases of the doping concentration, the HB separates from the MB and moves quickly to the high-binding energy region. The HB and MB are the direct results of the spin-charge separation while SB is the result of strong interaction between charge and spin parts. Therefore, our theoretical result predicts that the HB is more likely to be found at the low doping concentration, and it will be drowned in the background when the doping concentration is larger. Then with the temperature increases, the magnitude of the SB decreases, and it disappears at high temperature.

scholarly journals Dynamical Charge Structure Factor of a One-Dimensional Ionic Hubbard Model in the Low-Energy Region

2019 ◽  
Vol 88 (5) ◽  
pp. 054709
Author(s):  
Yuhei Komaki ◽  
Yuma Iwase ◽  
Shogo Yanagimatsu ◽  
Yoshiyuki Muta ◽  
Nobuya Maeshima ◽  
...  
Keyword(s):  
Hubbard Model ◽  
Structure Factor ◽  
Energy Region ◽  
Low Energy ◽  
Charge Structure ◽  
One Dimensional ◽  
Ionic Hubbard Model ◽  
Dynamical Charge

scholarly journals Broadband characterisation of the very intense TeV flares of the blazar 1ES 1959+650 in 2016

2020 ◽  
Vol 638 ◽  
pp. A14 ◽  
Author(s):  
◽  
V. A. Acciari ◽  
S. Ansoldi ◽  
L. A. Antonelli ◽  
A. Arbet Engels ◽  
...  
Keyword(s):  
Crab Nebula ◽  
Spectral Energy Distribution ◽  
High Energy ◽  
Spectral Energy ◽  
Proton Synchrotron ◽  
Large Area ◽  
X Ray ◽  
High Energy Peak ◽  
Energy Peak ◽  
Jet Power

1ES 1959+650 is a bright TeV high-frequency-peaked BL Lac object exhibiting interesting features like “orphan” TeV flares and broad emission in the high-energy regime that are difficult to interpret using conventional one-zone Synchrotron Self-Compton (SSC) scenarios. We report the results from the Major Atmospheric Gamma Imaging Cherenkov (MAGIC) observations in 2016 along with the multi-wavelength data from the Fermi Large Area Telescope (LAT) and Swift instruments. MAGIC observed 1ES 1959+650 with different emission levels in the very-high-energy (VHE, E >  100 GeV) γ-ray band during 2016. In the long-term data, the X-ray spectrum becomes harder with increasing flux and a hint of a similar trend is also visible in the VHE band. An exceptionally high VHE flux reaching ∼3 times the Crab Nebula flux was measured by MAGIC on the 13 and 14 of June, and 1 July 2016 (the highest flux observed since 2002). During these flares, the high-energy peak of the spectral energy distribution (SED) lies in the VHE domain and extends up to several TeV. The spectrum in the γ-ray (both Fermi-LAT and VHE bands) and the X-ray bands are quite hard. On 13 June and 1 July 2016, the source showed rapid variations in the VHE flux within timescales of less than an hour. A simple one-zone SSC model can describe the data during the flares requiring moderate to large values of the Doppler factors (δ ≥ 30−60). Alternatively, the high-energy peak of the SED can be explained by a purely hadronic model attributed to proton-synchrotron radiation with jet power Ljet ∼ 1046 erg s−1 and under high values of the magnetic field strength (∼100 G) and maximum proton energy (∼few EeV). Mixed lepto-hadronic models require super-Eddington values of the jet power. We conclude that it is difficult to get detectable neutrino emission from the source during the extreme VHE flaring period of 2016.

scholarly journals THE TWO TYPES OF CHERENKOV GLUONS AT LHC ENERGIES

2007 ◽  
Vol 16 (10) ◽  
pp. 3108-3114 ◽  
Author(s):  
I. M. DREMIN
Keyword(s):  
Energy Region ◽  
Scattering Amplitude ◽  
Cosmic Ray ◽  
High Energy ◽  
Positive Real Part ◽  
Forward Scattering ◽  
Low Energy ◽  
High Energy Region ◽  
Forward Scattering Amplitude ◽  
Positive Real

Beside comparatively low energy Cherenkov gluons observed at RHIC, there could be high energy gluons at LHC, related to the high energy region of positive real part of the forward scattering amplitude. In both cases they give rise to particles emitted along some cone. The characteristics of the cones produced by these two types of gluons are different. Therefore different experiments are needed to detect them. The cosmic ray event which initiated this idea is described in detail.

Electronic Structure and Dynamics at Organic Donor/Acceptor Interfaces

MRS Bulletin ◽  
2010 ◽  
Vol 35 (6) ◽  
pp. 443-448 ◽  
Author(s):  
Xiaoyang Zhu ◽  
Antoine Kahn
Keyword(s):  
Electronic Structure ◽  
Charge Separation ◽  
High Energy ◽  
Electronic Energy ◽  
Molecular Orbitals ◽  
Separation Process ◽  
Energy Gain ◽  
Donor Acceptor ◽  
The Difference ◽  
A Charge

AbstractWe present our understanding of the electronic energy landscape and dynamics of charge separation at organic donor/acceptor interfaces. The organic/organic interface serves as a valuable point of reference and plays an important role in emerging electronic and optoelectronic applications, particularly organic photovoltaics (OPVs). The key issue on electronic structure at organic donor/acceptor interfaces is the difference in the lowest unoccupied molecular orbitals or that in the highest occupied molecular orbitals. This difference represents an energy gain needed to overcome the exciton binding energy in a charge-separation process in OPV. A sufficiently large energy gain favors the formation of charge transfer (CT) states that are energetically close to the charge-separation state. At an organic donor/acceptor interface in an OPV device, these high-energy CT states, also called hot CT excitons, are necessary intermediates in a successful charge-separation process.

scholarly journals The low energy β-rays of radium E

1934 ◽  
Vol 147 (862) ◽  
pp. 442-454 ◽  
Keyword(s):  
Energy Loss ◽  
Continuous Spectrum ◽  
Energy Region ◽  
High Energy ◽  
Experimental Information ◽  
Low Energy ◽  
Expansion Chamber ◽  
High Energy Part ◽  
Energy Part ◽  
Γ Ray

The object of this work was to obtain information about the shape of the low energy end of the continuous β-ray spectrum of radium E, an element convenient because of its negligible γ-ray emission. The failure of theory to explain the continuous spectrum makes it of interest to obtain all possible experimental information, and although much is now known about the high energy part of the curve, the low energy region has remained obscure owing to certain experimental difficulties. The chief of these has been the contamination of the low energy end of the curve by rays reflected with unknown energy loss from the material on which the radioactive body was deposited. This effect can be eliminated by mounting it on sufficiently thin metal leaf so that no particles can be reflected with appreciable loss of energy. Such a source would be too weak to use in a magnetic spectrograph, and the method therefore adopted in this work was out to mount it in a Wilson expansion chamber and take stereoscopic photographs from which the ranges of any slow tracks formed could be measured, a method already used by the writer for radium D.

scholarly journals Probing Spin-Charge Separation in a Tomonaga-Luttinger Liquid

Science ◽  
2009 ◽  
Vol 325 (5940) ◽  
pp. 597-601 ◽  
Author(s):  
Y. Jompol ◽  
C. J. B. Ford ◽  
J. P. Griffiths ◽  
I. Farrer ◽  
G. A. C. Jones ◽  
...  
Keyword(s):  
Power Law ◽  
Charge Separation ◽  
Luttinger Liquid ◽  
Interaction Effects ◽  
Low Energy ◽  
One Dimensional ◽  
Energy Regime ◽  
Low Energies ◽  
Interacting Electrons

In a one-dimensional (1D) system of interacting electrons, excitations of spin and charge travel at different speeds, according to the theory of a Tomonaga-Luttinger liquid (TLL) at low energies. However, the clear observation of this spin-charge separation is an ongoing challenge experimentally. We have fabricated an electrostatically gated 1D system in which we observe spin-charge separation and also the predicted power-law suppression of tunneling into the 1D system. The spin-charge separation persists even beyond the low-energy regime where the TLL approximation should hold. TLL effects should therefore also be important in similar, but shorter, electrostatically gated wires, where interaction effects are being studied extensively worldwide.

scholarly journals Probing the Electronic Structure of Bulk Water at the Molecular Lengthscale with Angle-Resolved Photoelectron Spectroscopy

2020 ◽  
Author(s):  
Samer Gozem ◽  
Robert Seidel ◽  
Uwe Hergenhahn ◽  
Evgeny Lugovoy ◽  
Bernd Abel ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Photoelectron Spectroscopy ◽  
Anisotropy Parameter ◽  
High Energy ◽  
Bulk Water ◽  
Low Energy ◽  
Water Molecules ◽  
Neat Water ◽  
Energy Regime ◽  
The Individual

<div>We report a combined experimental and theoretical study of bulk water photoionization. Angular distributions of photoelectrons produced by ionizing the valence band of neat water using X-ray radiation (250-750 eV) show a limited (<30 %) decrease in the beta anisotropy parameter compared to the gas phase, indicating that the electronic structure of the individual water molecules can be probed. By theoretical modeling using high-level electronic structure methods, we show that in a high-energy regime photoionization of bulk can be described as an incoherent superposition of individual molecules, in contrast to a low-energy regime where photoionization probes delocalized entangled states of molecular aggregates. The two regimes-low energy versus high energy-are defined as limiting cases where the de Broglie wavelength of the photoelectron is either larger or smaller than the intermolecular distance between water molecules, respectively. The comparison of the measured and computed anisotropies reveals that at high kinetic energies the observed reduction in beta is mostly due to scattering rather than rehybridization due to solvation.</div>

scholarly journals Probing the Electronic Structure of Bulk Water at the Molecular Lengthscale with Angle-Resolved Photoelectron Spectroscopy

2020 ◽  
Author(s):  
Samer Gozem ◽  
Robert Seidel ◽  
Uwe Hergenhahn ◽  
Evgeny Lugovoy ◽  
Bernd Winter ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Photoelectron Spectroscopy ◽  
Anisotropy Parameter ◽  
High Energy ◽  
Bulk Water ◽  
Low Energy ◽  
Water Molecules ◽  
Neat Water ◽  
Energy Regime ◽  
The Individual

<div>We report a combined experimental and theoretical study of bulk water photoionization. Angular distributions of photoelectrons produced by ionizing the valence band of neat water using X-ray radiation (250-750 eV) show a limited (<30 %) decrease in the beta anisotropy parameter compared to the gas phase, indicating that the electronic structure of the individual water molecules can be probed. By theoretical modeling using high-level electronic structure methods, we show that in a high-energy regime photoionization of bulk can be described as an incoherent superposition of individual molecules, in contrast to a low-energy regime where photoionization probes delocalized entangled states of molecular aggregates. The two regimes-low energy versus high energy-are defined as limiting cases where the de Broglie wavelength of the photoelectron is either larger or smaller than the intermolecular distance between water molecules, respectively.</div>

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