Symmetries and conservation of spin angular momentum, helicity, and chirality in photonic time-varying media

被引:0
作者
Jajin, Mohsen Mohammadi [1 ]
Vazquez-Lozano, J. Enrique [1 ]
Liberal, Inigo [1 ]
机构
[1] Univ Publ Navarra, Inst Smart Cities, Dept Elect Elect & Commun Engn, Pamplona 31006, Spain
基金
欧盟地平线“2020”;
关键词
ELECTROMAGNETIC ENERGY; METAMATERIALS; PROPAGATION; INTERFACES; DISPERSION; LAWS;
D O I
10.1103/PhysRevA.110.063522
中图分类号
O43 [光学];
学科分类号
070207 ; 0803 ;
摘要
Polarization-dependent dynamical properties of light such as the spin angular momentum (SAM), helicity, and chirality are conserved quantities in free space. Despite their similarities on account of their relationship with a circular state of polarization, SAM, helicity, and chirality emerge from distinct symmetries, which endows them with different physical meanings, properties, and practical applications. In this work we investigate the behavior of such quantities in time-varying media (TVM), i.e., how a temporal modulation impacts their symmetries and conservation laws. Our results demonstrate that the SAM is conserved for any time modulation, helicity is only preserved in impedance-matched time modulations, and chirality is not conserved. In addition, the continuity equations highlight the dependence of the chirality on the energy content of the fields. These results provide additional insights into the similarities and differences between SAM, helicity, and chirality, as well as their physical meaning. Furthermore, our theoretical framework provides an alternative perspective to analyze polarization-dependent light-matter interactions in TVM.
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页数:11
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  • [1] Engheta N., Metamaterials with high degrees of freedom: Space, time, and more, Nanophotonics, 10, (2021)
  • [2] Galiffi E., Tirole R., Yin S., Li H., Vezzoli S., Huidobro P. A., Silveirinha M. G., Sapienza R., Alu A., Pendry J. B., Photonics of time-varying media, Adv. Photonics, 4, (2022)
  • [3] Yin S., Galiffi E., Alu A., Floquet metamaterials, eLight, 2, (2022)
  • [4] Yuan L., Fan S., Temporal modulation brings metamaterials into new era, Light Sci. Appl, 11, (2022)
  • [5] Engheta N., Four-dimensional optics using time-varying metamaterials, Science, 379, (2023)
  • [6] Shlivinski A., Hadad Y., Beyond the Bode-Fano bound: Wideband impedance matching for short pulses using temporal switching of transmission-line parameters, Phys. Rev. Lett, 121, (2018)
  • [7] Sounas D. L., Alu A., Non-reciprocal photonics based on time modulation, Nat. Photonics, 11, (2017)
  • [8] Liberal I., Vazquez-Lozano J. E., Pacheco-Pena V., Quantum antireflection temporal coatings: Quantum state frequency shifting and inhibited thermal noise amplification, Laser Photonics Rev, 17, (2023)
  • [9] Akbarzadeh A., Chamanara N., Caloz C., Inverse prism based on temporal discontinuity and spatial dispersion, Opt. Lett, 43, (2018)
  • [10] Pacheco-Pena V., Engheta N., Temporal aiming, Light Sci. Appl, 9, (2020)