狄拉克半金属中电调谐古斯-汉欣位移

Electrically tunable Goos-H?nchen shift in Dirac semimetal

古斯-汉欣位移在光束反射中有重要意义.理论分析并数值验证了线偏振光入射到狄拉克半金属上的古斯-汉欣位移.通过辨别介电函数的实部,确定狄拉克半金属的高损耗和低损耗电介质响应和金属响应.仅在金属响应区,大的相位跃变引起大的古斯-汉欣位移,可用作红外滤波.并且在金属响应区,TE偏振的古斯-汉欣位移永为正且接近零,但随着费米能增加TM偏振的古斯-汉欣位移总是为负且有最小值.通过电调谐狄拉克半金属的费米能,可以调控介电函数和古斯-汉欣位移,反之古斯-汉欣位移能够用来测量费米能.

Goos-H?nchen(GH)shift is significant in the reflection of optical beams.Here the GH shift of the linearly polarized light incident on Dirac semimetal is theoretically and numerically investigated.Through distinguishing the real part of the dielectric function,Dirac semimetal is identified as the high and low loss dielectric response,and the metallic response.It is found that the large phase jump causes the large GH shift only in the metallic region,which may provide a strategy for infrared filtering.And in the metallic region,the TE polarized GH shifts are always positive and close to zero,while the TM polarized GH shifts accompanied by an increasing Fermi energy are always negative and only of minimal values.By electrically tuning the Fermi energy of Dirac semimetal,the dielectric function and GH shifts can be manipulated,and inversely the GH shifts can be used to measure Fermi energy.