Unlike photons, which are conveniently handled by mirrors and optical fibres without loss of coherence, atoms lose their coherence via atom-atom atom-wall interactions. This decoherence deteriorates the performance atomic clocks magnetometers, also hinders miniaturisation. Here we report a novel platform for precision spectroscopy. Ultracold strontium inside kKagome-lattice hollow-core photonic crystal fibre (HC-PCF) transversely confined an lattice to prevent from interacting with wall. By...

The recent growing interest in terahertz (THz) and sub-THz science technology is due to its many important applications physics, astronomy, chemistry, biology, medicine. We review the problem of linear non-linear THz Josephson plasma waves layered superconductors their excitations produced by moving vortices. start discussing coupled sine-Gordon equations for gauge-invariant phase difference order parameter junctions, taking into account effect breaking charge neutrality, deriving spectrum...

We predict the existence of surface waves in layered superconductors THz frequency range, below Josephson plasma omega J. This wave propagates along vacuum-superconductor interface and dampens both transverse directions out (i.e., towards superconductor vacuum). is first prediction propagating any superconductor. These predicted are important for different phenomena, including complete suppression specular reflection from a sample (Wood's anomalies) huge enhancement absorption (which can be...

We show that surface electromagnetic waves (SEMWs) propagating along two-dimensional (2D) interfaces separating different metamaterials can behave analogously to 3D in either usual or left-handed media, depending on the permeabilities and/or permittivities of two materials forming interface. derive conditions when SEMWs carry energy opposite phase velocity. In analogy three-dimensional (3D) we both an anomalous Cherenkov emission and a reversed Doppler effect. also predict negative...

We analyze the use of layered superconductors as strongly anisotropic metamaterials, which can possess negative-refractive-index in a wide frequency range. Superconductors are particular interest because they have potential to support low losses, is critical for applications such super-resolution imaging. show that low-${T}_{c}$ ($s$-wave) be used construct heterostructures with losses $T⪡{T}_{c}$. However, real part their in-plane effective permittivity very large, making coupling into...

A theory of systems with long-range correlations based on the consideration binary N-step Markov chains is developed. In our model, conditional probability that ith symbol in chain equals zero (or unity) a linear function number unities among preceding N symbols. The correlation and distribution functions as well variance symbols words arbitrary length L are obtained analytically numerically. If persistent not extremely strong, shown to be nonlinearly dependent L. self-similarity studied...

Within the framework of Drude dispersive model, we predict an unusual nonmonotonic temperature dependence Casimir force for thin metal films. For certain conditions, this decreases with due to decrease metallic conductivity, whereas increases at high temperatures increase thermal radiation pressure. We consider attraction a film to: either (i) bulk ideal planar boundary, or (ii) sphere (lens). The experimental observation predicted decreasing can put end long-standing discussion on role...

We predict a new branch of surface Josephson plasma waves (SJPWs) in layered superconductors for frequencies higher than the frequency. In this frequency range, permittivity tensor components along and transverse to layers have different signs, which is usually associated with negative refraction. However, these frequencies, bulk cannot be matched incident reflected vacuum, and, instead negative-refractive properties, abnormal modes appear within band expected modes. also discuss excitation...

We show that a moving Josephson vortex in spatially modulated layered superconductors generates out-of-plane THz radiation. Remarkably, the magnetic and in-plane electric fields radiated are of same order, which is very unusual for any good-conducting medium. Therefore, radiation can be emitted to vacuum without standard impedance mismatch problem. Thus, proposed tunable emitter more efficient than one radiates only along $ab$-plane.

A contactless method for determining the local critical current density ${\mathit{J}}_{\mathit{c}}$(B) and effective magnetic permeability of \ensuremath{\mu} ceramic superconductors is presented. Using this we have carried out systematic investigations field temperature dependence in ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{7\mathrm{\ensuremath{-}}\mathrm{\ensuremath{\delta}}}$ samples with different microstructures. The results show that character Josephson junctions sintered...

We predict unusual (for non-relativistic quantum mechanics) electron states in graphene, which are localized within a finite-width potential barrier. The density of the sufficiently high and/or wide graphene barrier exhibits number singularities at certain values energy. Such provide oscillations both transport (e.g. conductivity) and thermodynamic properties graphene—when increasing height width, similarly to well-known Shubnikov–de-Haas (SdH) conductivity pure metals. However, here...

We discuss the propagation of symmetric and antisymmetric Josephson plasma waves in a slab layered superconductor clad between two identical dielectrics. predict branches surface terahertz frequency range, one above another below frequency. Apart from this, there exists discrete set waveguide modes with electromagnetic fields oscillating across thickness decaying exponentially away slab. consider excitation predicted by means attenuated-total-reflection method. It is shown that for specific...

The suppression of the static magnetic moment M a superconducting plate in critical state by sweeping field $\stackrel{\ensuremath{\rightarrow}}{h}(t),$ applied perpendicularly to dc $\mathcal{H}\ensuremath{\rightarrow},$ has been studied experimentally and theoretically. For every quarter-period $h(t)$ changing polarity with an amplitude ${h}_{0},$ noticeable decrease can be observed both for paramagnetic diamagnetic initial states even small ${h}_{0}$ compared $\mathcal{H}.$ Numerical...

We show that unusual nonlinear self-sustained waves, called waveguide modes (NWGMs), can propagate along thin slabs of layered superconductors. these waves are stable in the main approximation for extremely anisotropic superconductors if wave amplitude is smaller than a critical value. These have no analogs among linear Josephson plasma and do not exist thick samples. The magnetic field NWGM distributed symmetrically with respect to middle slab, decays far from sample, change its sign...

A fundamental property of wave propagation is Anderson localization, which affects the transfer information, energy, mass, and charge in disordered media. This localization can manifest itself via, e.g., metal-insulator transition. We exactly map behavior a quantum particle moving potential with correlated disorder to sub-terahertz either Josephson chains or superconducting multilayers. When junction parameters vary randomly, sub-THz electromagnetic waves cannot propagate through these...

A theory of additive Markov chains with long-range memory is used to describe the correlation properties coarse-grained literary texts. The complex structure correlations in texts revealed. Antipersistent at small distances, $L\ensuremath{\lesssim}300$, and persistent ones $L\ensuremath{\gtrsim}300$ define this nontrivial structure. For some concrete examples texts, functions are obtained their power-law behavior long distances disclosed. This property shown be a cause self-similarity...

We predict a new class of excitations propagating along Josephson vortex in two-dimensional junctions. These are associated with the distortion line and have an analogy shear waves solid mechanics. Their shapes can arbitrary profile, which is retained when propagating. derive universal analytical expression for energy shape excitations, investigate their influence on dynamics line, discuss conditions where such be created. Finally, we show that play role clock relativistically moving suggest...

We predict surface electromagnetic waves propagating across the layers of intrinsic Josephson junctions. find spectrum waves, and study distribution field inside outside superconductor. The profile amplitude oscillations electric-field component such is peculiar: initially, it increases toward center superconductor and, after reaching a crossover point, decreases exponentially.

We predict a complete TM-TE transformation of the polarization terahertz electromagnetic waves reflected from strongly anisotropic boundary layered superconductor. consider case when wave is incident on superconductor dielectric prism separated sample by thin vacuum gap. The physical origin predicted phenomenon similar to Wood anomalies known in optics, and related resonance excitation oblique surface waves. also discuss dispersion relation for these waves, propagating along at some angle...

We predict the coexistence of both TE- and TM-polarized localized electromagnetic waves that can propagate \emph{in same frequency range} along a graphene layer inserted in photonic crystal. In addition, we studied excitation these modes by an external wave have shown resonance peaks sample transmissivity should be observed due to waves, independently polarization exciting wave. The simplicity derived dispersion relations for possibility excite polarizations provide method measuring conductivity.