Spontaneous Lorentz violation: the case of infrared QED

Balachandran, A. P.
Kürkcüoğlu, Seçkin
de Queiroz, A. R.
It is by now clear that the infrared sector of quantum electrodynamics (QED) has an intriguingly complex structure. Based on earlier pioneering work on this subject, two of us recently proposed a simple modification of QED by constructing a generalization of the U(1) charge group of QED to the "Sky" group incorporating the well-known spontaneous Lorentz violation due to infrared photons, but still compatible in particular with locality (Balachandran and Vaidya, Eur Phys J Plus 128:118, 2013). It was shown that the "Sky" group is generated by the algebra of angle-dependent charges and a study of its superselection sectors has revealed a manifest description of spontaneous breaking of the Lorentz symmetry. We further elaborate this approach here and investigate in some detail the properties of charged particles dressed by the infrared photons. We find that Lorentz violation due to soft photons may be manifestly codified in an angle-dependent fermion mass, modifying therefore the fermion dispersion relations. The fact that the masses of the charged particles are not Lorentz invariant affects their spin content, and time dilation formulas for decays should also get corrections.


Quantum decoherence and quantum state diffusion formalism
Dumlu, Cesim Kadri; Turgut, Sadi; Department of Physics (2007)
Foundational problems of quantum theory, regarding the appearance of classicality and the measurement problem are stated and their link to studies of open quantum systems is discussed. This study's main aim is to analyze the main approaches that are employed in the context of open quantum systems. The general form of Markovian master equations are derived by a constructive approach. The Quantum State Diffusion (QSD) formalism is stressed upon as an alternative method to the master equations. Using the Calde...
Nonlinear optical properties of semiconductor heterostructures
Yıldırım, Hasan; Tomak, Mehmet; Department of Physics (2006)
The nonlinear optical properties of semiconductor heterostructures, such as GaAsAl/GaAs alloys, are studied with analytic and numerical methods on the basis of quantum mechanics. Particularly, second and third-order nonlinear optical properties of quantum wells described by the various types of confining potentials are considered within the density matrix formalism. We consider a Pöschl-Teller type potential which has been rarely considered in this area. It has a tunable asymmetry parameter, making it a goo...
Interacting electrons in a 2D quantum dot
Akman, N; Tomak, Mehmet (1999-04-01)
The exact numerical diagonalization of the Hamiltonian of a 2D circular quantum dot is performed for 2, 3, and 4 electrons. The results an compared with those of the perturbation theory. Our numerical results agree reasonably well for small values of the dimensionless coupling constant lambda = a/a(B) where a is the dot radius and a(B) is the effective Bohr radius. Exact diagonalization results are compared with the classical predictions, and they are found to be almost coincident for large lambda values.
ILAIWI, KF; Tomak, Mehmet (1991-01-01)
The polarization of a quantum electron confined in a parabolic quantum well in the presence of a uniform electric field is calculated numerically. We find positive polarization for both ground and the first excited states.
Thermal characterisation of quantum cascade lasers with Fabry Perot modes
Gundogdu, Sinan; Pisheh, Hadi Sedaghat; Demir, Abdullah; Guenoven, Mete; AYDINLI, ATİLLA; Sirtori, Carlo (2018-04-26)
Quantum cascade lasers are coherent light sources that rely on intrersubband transition in periodic semiconductor quantum well structures. They operate at frequencies from mid-infrared to terahertz. In cases of long wavelength and typical low thermal conductivity of the active region, temperature rise in the active region during operation is a major concern. Thermal conductivity of QCL epi-layers differ significantly from the values of bulk semiconductors and measurement of the thermal conductivity of epi-l...
Citation Formats
A. P. Balachandran, S. Kürkcüoğlu, A. R. de Queiroz, and S. VAİDYA, “Spontaneous Lorentz violation: the case of infrared QED,” EUROPEAN PHYSICAL JOURNAL C, pp. 0–0, 2015, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/34426.