“…It is apparent from this plot that the crossover between two distinct limits -from GOE to GUE -takes place at relatively small values of |Q| (which is the parameter responsible for the imaginary part of a dynamical matrix). A high sensitivity of correlations in the spectrum of optical phonons in a complex crystal to the rise of an imaginary part of D is in agreement with what is known about the crossover between GOE and GUE symmetry classes in chaotic electronic billiards [6], and it seems that it cannot be reduced to a trivial mixing of two typical (GOE and GUE) distribution functions [7][8][9].…”
We study spectral statistics of lattice modes in a disordered crystal and in a crystal with a complex unit cell. The correlations of the eigenmode frequencies of a block of a disordered solid is found to obey the GOE WignerDyson statistics. In contrast, the set of eigenfrequencies of a crystal with a complex unit cell taken at the same point Q = 0 in the Brillouin zone exhibit correlations specific to the GUE universality class.
“…It is apparent from this plot that the crossover between two distinct limits -from GOE to GUE -takes place at relatively small values of |Q| (which is the parameter responsible for the imaginary part of a dynamical matrix). A high sensitivity of correlations in the spectrum of optical phonons in a complex crystal to the rise of an imaginary part of D is in agreement with what is known about the crossover between GOE and GUE symmetry classes in chaotic electronic billiards [6], and it seems that it cannot be reduced to a trivial mixing of two typical (GOE and GUE) distribution functions [7][8][9].…”
We study spectral statistics of lattice modes in a disordered crystal and in a crystal with a complex unit cell. The correlations of the eigenmode frequencies of a block of a disordered solid is found to obey the GOE WignerDyson statistics. In contrast, the set of eigenfrequencies of a crystal with a complex unit cell taken at the same point Q = 0 in the Brillouin zone exhibit correlations specific to the GUE universality class.
“…(9) and (12). To simplify the following discussion, we explicitly display the fact that the integration over all the angles % : sj is done after the integration over all other variables have been performed and write the integrals I l 3 l 4 [ f ] in the form …”
“…A first substantial simplification arises when we adopt the procedure developed in Ref. [9]. We write the coset matrices T as the product of two matrices T C and T D ,…”
“…Motivated by the paper by Altland et al [18], we write our coset matrices T as products of matrices T I obtained by exponentiating the coset generators anticommuting with { 3 , and matrices T 0 obtained by exponentiating the coset generators commuting with { 3 ,…”
Section: Parametrization Of the Saddle Point Manifoldmentioning
We complement a recent calculation (P.B. Gossiaux and the present authors,
Ann. Phys. (N.Y.) in press) of the autocorrelation function of the conductance
versus magnetic field strength for ballistic electron transport through
microstructures with the shape of a classically chaotic billiard coupled to
ideal leads. The function depends on the total number M of channels and the
parameter t which measures the difference in magnetic field strengths. We
determine the leading terms in an asymptotic expansion for large t at fixed M,
and for large M at fixed t/M. We compare our results and the ones obtained in
the previous paper with the squared Lorentzian suggested by semiclassical
theory.Comment: submitted to Annals of Physics (N.Y.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.