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We find that a new type of non-reciprocal modes exist at an interface between two emph{parity-time} ($mathcal{PT}$) symmetric magnetic domains (MDs) near the frequency of zero effective permeability. The new mode is non-propagating and purely magneti c when the two MDs are semi-infinite while it becomes propagating in the finite case. In particular, two pronounced nonreciprocal responses could be observed via the excitation of this mode: one-way optical tunneling for oblique incidence and unidirectional beam shift at normal incidence. When the two MDs system becomes finite in size, it is found that perfect-transmission mode could be achieved if $mathcal{PT}$-symmetry is maintained. The unique properties of such an unusual mode are investigated by analytical modal calculation as well as numerical simulations. The results suggest a new approach to the design of compact optical isolator.
We propose a vortex-like metamaterial device that is capable of transferring image along a spiral route without losing subwavelength information of the image. The super-resolution image can be guided and magnified at the same time with one single des ign. Our design may provide insights in manipulating super-resolution image in a more flexible manner. Examples are given and illustrated with numerical simulations.
We demonstrate theoretically the existence of one-way Tamm plasmon-polaritons on the interface between magnetophotonic crystals and conducting metal oxides. In contrast to conventional surface plasmon-polaritons (SPPs), Tamm plasmon-polariton (TPPs) occur at frequencies above the bulk plasma frequency of the conducting materials, provided that the dispersion curves of such surface modes lie outside the light cone for the conducting oxides and simultaneously fall into the photonic band gap of the magnetophotonic crystal. The nonreciprocal properties of TPPs are caused by violation of the periodicity and time reversal symmetry in the structure. Calculations on the field distribution and transmission spectra through the structure are employed to confirm the theoretical results, which could potentially impact on a broad range of SPP-related phenomena in applications.
54 - Runbing Li , Lin Zhou , Jin Wang 2008
We demonstrate a technique for directly measuring the quadratic Zeeman shift using stimulated Raman transitions.The quadratic Zeeman shift has been measured yielding [delta][nju] = 1296.8 +/-3.3 Hz/G^{2} for magnetically insensitive sublevels (5S1/2, F = 2,mF = 0 -> 5S1/2, F = 3,mF = 0) of ^{85}Rb by compensating the magnetic eld and cancelling the ac Stark shift. We also measured the cancellation ratio of the differential ac Stark shift due to the imbalanced Raman beams by using two pairs of Raman beams ([sigma]^{+}, [sigma]^{+}) and it is 1:3.67 when the one-photon detuning is 1.5 GHz in the experiment.
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