We report on the influence of a periodic potential on the fractional quantum Hall effect (FQHE) states in monolayer graphene. We have shown that for two values of the magnetic flux per unit cell (one-half and one-third flux quantum) an increase of the periodic potential strength results in a closure of the FQHE gap and appearance of gaps due to the periodic potential. In the case of one-half flux quantum this causes a change of the ground state and consequently the change of the momentum of the system in the ground state. While there is also crossing between low-lying energy levels for one-third flux quantum, the ground state does not change with the increase of the periodic potential strength and is always characterized by the same momentum. Finally, it is shown that for one-half flux quantum the emergent gaps are due entirely to the electron-electron interaction, whereas for the one-third flux quantum per unit cell these are due to both non-interacting electrons (Hofstadter butterfly pattern) and the electron-electron interaction.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1088/0953-8984/27/18/185301 | DOI Listing |
Rev Sci Instrum
December 2024
Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, Aoba-ku, Sendai, Miyagi 980-8577, Japan.
An objective soft x-ray flat-field spectrograph employing a laminar-type bilayer coated, varied-line-spacing, spherical grating was designed to improve the detection limit and sensitivity of soft x-ray flat-field spectrographs in a region of 250-550 eV. As a design criterion, spectral flux, SF, [Hatano et al., Appl.
View Article and Find Full Text PDFJ Phys Condens Matter
December 2024
Departamento de Física, Facultad de Ciencias, Universidad Nacional Autónoma de México, Circuito interior s/n, Colonia Universidad Nacional Autónoma de México, Coyoacán, C.P. 0451 Ciudad Universitaria, Ciudad de México, México, Ciudad de Mexico, 04510, MEXICO.
Magnetic fields can be introduced into discrete models of quantum systems by the Peierls substitution. For tight-binding Hamiltonians, the substitution results in a set of (Peierls) phases that are usually calculated from the magnetic vector potential. As the potential is not unique, a convenient gauge can be chosen to fit the geometry and simplify calculations.
View Article and Find Full Text PDFPLoS One
December 2024
Department of Electrical Engineering, Stanford University, Stanford, California, United States of America.
We present a model for the noise and inherent stochasticity of fluorescence signals in both continuous wave (CW) and time-gated (TG) conditions. When the fluorophores are subjected to an arbitrary excitation photon flux, we apply the model and compute the evolution of the probability mass function (pmf) for each quantum state comprising a fluorophore's electronic structure, and hence the dynamics of the resulting emission photon flux. Both the ensemble and stochastic models presented in this work have been verified using Monte Carlo molecular dynamic simulations that utilize the Gillespie algorithm.
View Article and Find Full Text PDFPhys Rev Lett
December 2024
Institute for Advanced Study, Tsinghua University, Beijing 100084, China.
The nonintegrable higher spin Kitaev honeycomb model has an exact Z_{2} gauge structure, which exclusively identifies quantum spin liquid in the half-integer spin Kitaev model. But its constraints for the integer-spin Kitaev model are much limited, and even trivially gapped insulators cannot be excluded. The physical implications of exact Z_{2} gauge structure, especially Z_{2} fluxes, in integer-spin models remain largely unexplored.
View Article and Find Full Text PDFAdv Mater
December 2024
College of Physics and Energy, Fujian Normal University, Fuzhou, Fujian, 350117, P. R. China.
Laser-driven projection displays face a critical challenge in developing laser-excitable and high-performance narrowband green emitters. Herein, new AlO-LaMgAlO: Mn (AlO-LMA: Mn) transparent composite ceramics are reported via high-temperature vacuum sintering, which produces a high-color-purity (95.4%) green emission with full width at half maximum of 24 nm and superior thermal and moisture and laser irradiation stability.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!