**11. References**

Abdumalikov, A. A.; Astafiev, Jr., O.; Zagoskin, A. M.; Pashkin, Y. A.; Nakamura, Y. & Tsai, J. S. (2010). Solitons in Weakly Nonlocal Media with Cubic-Quintic Nonlinearity. *Physical Review Letters,* Vol 104, 193601(1-4), ISSN 0031-9007

As the microscopic electric polarizability as well as the electric permittivity of the EIT medium are caused by the atomic energy level transition processes from the ground state to the excited states, in which the quantum interference relevant to atomic phase coherence is involved, the reflectance and transmittance of an EIT-based periodic layered medium are

The LHM-EIT-based periodic layered medium has also been considered (in Sections 6 and 7). Since there are left-handed layers embedded in the layered medium, and the periodic EIT layers would act as a potential barrier for the incident electromagnetic wave, the absolute values of the real or imaginary part of the reflection coefficient in some frequency ranges would be more than unity due to the Klein tunneling. The present photonic analog of the Klein tunneling might be used for designing frequency-sensitive photonic transistors. We expect that some new photonic devices (e.g., logic and functional gates) and sensitively switchable devices (fundamental building blocks in, e.g., photonic microcircuits on silicon, in which light replaces electrons), which would find new applications in photonic quantum information processing, would be achieved by taking advantage of such an effect of *coherent* 

The present scheme can be generalized to the cases of four-level EIT systems, where two control fields and one probe field drive the atomic level transitions (Shen, 2007; Shen & Zhang, 2007; Gharibi et al., 2009; Shen, 2010). Obviously, the optical response in such a four-level EITbased photonic crystal would be more sensitive to the probe frequency than in a three-level EIT photonic crystal presented in this paper. Apart from this intriguing property, there are also interesting applications based on the four-level EIT photonic crystal, e.g., some examples of photonic devices (e.g., multi-input logic gates), in which the control fields and the transmitted probe field act as the input and output signals, respectively, can be designed. We expect that all these new optical properties relevant to quantum coherence, including their applications to

This work is supported by National Science Council under Grant Nos. NSC 99-2811-M-216- 001, NSC 99-2112-M-216-002 and NSC100-2112-M-216-002. The author Shen acknowledges the support of National Natural Science Foundation of China under Grant Nos. 11174250, 60990320, Natural Science Foundation of Zhejiang Province, China, under Grant No.Y6100280, and the Fundamental Research Funds for the Central Universities of China. The author Shen is also grateful to State Key Laboratory of Modern Optical Instrumentations (Zhejiang University, China) for its financial support (2010-2012). Correspondence and requests for materials relevant to the present work can be addressed to

Abdumalikov, A. A.; Astafiev, Jr., O.; Zagoskin, A. M.; Pashkin, Y. A.; Nakamura, Y. & Tsai,

*Physical Review Letters,* Vol 104, 193601(1-4), ISSN 0031-9007

J. S. (2010). Solitons in Weakly Nonlocal Media with Cubic-Quintic Nonlinearity.

photonic devices, could be realized experimentally in the near future.

shown to be quite sensitive to the probe frequency.

*switching control* (in Section 8).

**10. Acknowledgments** 

**11. References** 

Jian Qi Shen (jqshen@coer.zju.edu.cn).


**Part 3** 

**Photonic Crystal Fiber** 

