اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدUniversal spin-resolved thermal radiation laws for nonreciprocal bianisotropic media
209
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
A chiral absorber of light can emit spin-polarized (circularly polarized) thermal radiation based on Kirchhoffs law which equates spin-resolved emissivity with spin-resolved absorptivity for reciprocal media at thermal equilibrium. No such law is known for nonreciprocal media. In this work, we discover three spin-resolved Kirchhoffs laws of thermal radiation applicable for both reciprocal and nonreciprocal planar media. In particular, these laws are applicable to multi-layered or composite slabs of generic bianisotropic material classes which include (uniaxial or biaxial) birefringent crystals, (gyrotropic) Weyl semimetals, magnetized semiconductors, plasmas, ferromagnets and ferrites, (magnetoelectric) topological insulators, metamaterials and multiferroic media. We also propose an experiment to verify these laws using a single system of doped Indium Antimonide (InSb) thin film in an external magnetic field. Furthermore, we reveal a surprising result that the planar slabs of all these material classes can emit partially circularly polarized thermal light without requiring any surface patterning, and identify planar configurations which can experience nontrivial thermal optomechanical forces and torques upon thermal emission into the external environment at lower temperature (nonequilibrium). Our work also provides a new fundamental insight of detailed balance of angular momentum (in addition to energy) of equilibrium thermal radiation, and paves the way for practical functionalities based on thermal radiation using nonreciprocal bianisotropic materials.
قيم البحث
اقرأ أيضاً
For two electrically small nonreciprocal scatterers an analytical electromagnetic model of polarizabilities is developed. Both particles are bianisotropic: the so-called Tellegen-omega particle and moving-chiral particle. Analytical results are compa
red to the full-wave numerical simulations. Both models satisfy to main physical restrictions and leave no doubts in the possibility to realize these particles experimentally. This paper is a necessary step towards applications of nonreciprocal bianisotropic particles such as perfect electromagnetic isolators, twist polarizers, thin-sheet phase shifters, and other devices.
Kirchhoff s law is one of the most fundamental law in thermal radiation. The violation of traditional Kirchhoff s law provides opportunities for higher energy conversion efficiency. Various micro-structures have been proposed to realize single-band n
onreciprocal thermal emitters. However, dual-band nonreciprocal thermal emitters remain barely investigated. In this paper, we introduce magneto-optical material into a cascading one-dimensional (1-D) magnetophotonic crystal (MPC) heterostructure composed of two 1-D MPCs and a metal layer. Assisted by the nonreciprocity of the magneto-optical material and the coupling effect of two optical Tamm states (OTSs), a dual-band nonreciprocal lithography-free thermal emitter is achieved. The emitter exhibits strong dual-band nonreciprocal radiation at the wavelengths of 15.337 um and 15.731 um when the external magnetic field is 3 T and the angle of incidence is 56 degree. Besides, the magnetic field distribution is also calculated to confirm that the dual-band nonreciprocal radiation originates from the coupling effect between two OTSs. Our work may pave the way for constructing dual-band and multi-band nonreciprocal thermal emitters.
Metal nanoantennas supporting localized surface plasmon resonances have become an indispensable tool in bio(chemical) sensing and nanoscale imaging applications. The high plasmon-enhanced electric field intensity in the visible or near-IR range that
enables the above applications may also cause local heating of nanoantennas. We present a design of hybrid optical-thermal antennas that simultaneously enable intensity enhancement at the operating wavelength in the visible and nanoscale local temperature control. We demonstrate a possibility to reduce the hybrid antenna operating temperature via enhanced infrared thermal emission. We predict via rigorous numerical modeling that hybrid optical-thermal antennas that support high-quality-factor photonic-plasmonic modes enable up to two orders of magnitude enhancement of localized electric fields and of the optical power absorbed in the nanoscale metal volume. At the same time, the hybrid antenna temperature can be lowered by several hundred degrees with respect to its all-metal counterpart under continuous irradiance of 104-105 W/m2. The temperature reduction effect is attributed to the enhanced radiative cooling, which is mediated by the thermally-excited localized surface phonon polariton modes. We further show that temperature reduction under even higher irradiances can be achieved by a combination of enhanced radiative and convective cooling in hybrid antennas. Finally, we demonstrate how hybrid optical-thermal antennas can be used to achieve strong localized heating of nanoparticles while keeping the rest of the optical chip at low temperature.
We predict the simultaneous occurrence of two fundamental phenomena for metal nanoparticles possessing sharp corners: First, the main plasmonic dipolar mode experiences strong red shift with decreasing corner curvature radius; its resonant frequency
is controlled by the apex angle of the corner and the normalized (to the particle size) corner curvature. Second, the split-off plasmonic mode experiences strong localization at the corners. Altogether, this paves the way for tailoring of metal nano-structures providing wavelength-selective excitation of localized plasmons and a strong near-field enhancement of linear and nonlinear optical phenomena.
The interplay of spin angular momentum and thermal radiation is a frontier area of interest to nanophotonics as well as topological physics. Here, we show that a thick planar slab of a nonreciprocal material, despite being at thermal equilibrium with
its environment, can exhibit nonzero photon spin angular momentum and nonzero radiative heat flux in its vicinity. We identify them as the persistent thermal photon spin (PTPS) and the persistent planar heat current (PPHC) respectively. With a practical example system, we reveal that the fundamental origin of these phenomena is connected to spin-momentum locking of thermally excited evanescent waves. We also discover spin magnetic moment of surface polaritons in nonreciprocal photonics that further clarifies these features. We then propose a novel thermal photonic imaging experiment based on Brownian motion that allows one to witness these surprising features by directly looking at them using a lab microscope. We further demonstrate the universal behavior of these near-field thermal radiation phenomena through a comprehensive analysis of gyroelectric, gyromagnetic and magneto-electric nonreciprocal materials. Together, these results expose a surprisingly little explored research area of thermal spin photonics with prospects for new avenues related to non-Hermitian topological photonics and radiative heat transport.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
