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Left-handedness with three zero-absorption windows is achieved in a triple-quantum-dot system. With the typical parameters of a GaAs/AlGaAs heterostructure, the simultaneous negative relative electric permittivity and magnetic permeability are obtained by the adjustable incoherent pumping field and two inter-dot tunnelings. Furthermore, three zero-absorption windows in the left-handedness frequency bands are observed. The lefthandedness with zero-absorption in the solid state heterostructure may solve the challenges not only in the left-handed materials achieved by the photonic resonant scheme but also in the application of negative refractive materials with a large amount of absorption.

385In recent years there has been a huge interest in semiconductor quantum wells (SQWs), on account of the intersubband transitions (ISBTs) in SQWs are believed to have great potential applications in solid state optoelectronics and quantum information sci ence [1][2][3][4]. In many cases the characteristics of ISBT dephasing mechanisms in SQWs behave essentially as "artificial atoms," which allowed us to regard the SQW as a single quantum object for many kinds of quantum optical phenomena, in which the nonlinear quantum optical phenomena have been extensively discussed, such as Kerr nonlinearity [5], ultrafast all optical switching [6], coherent population trapping [7], elec tromagnetically induced transparency [8-10], gain without inversion [11], enhancing index of refraction [12], and other novel phenomena [13][14][15][16][17][18]. But not only that, the devices based on ISBTs in SQWs also have many inherent advantages that the atomic sys tems don't have, such as the high nonlinear optical coefficients, the large transition energies and electric dipole moments for the small effective electron mass, the great flexibilities in symmetries design as well as in devices design by choosing the materials and structure dimensions.In this work, we investigate the refractive index in a bulk SQW nanostructure via electromagnetically induced chirality. And the results demonstrate the large and tunable NRI can be realized by the coupling laser field and the relative phase. The SQW samples we simulate here are reported to be grown by the molecu lar beam epitaxy (MBE) method and each contains a 4.8 nm In 0.47 Ga 0.53 As/0.2 nm Al 0.48 In 0.52 As/4.8 nm ¶ The article is published in the original.In 0.47 Ga 0.53 As coupled quantum well, separated by a 36 nm Al 0.48 In 0.52 As modulation doped barriers [19,20]. And the transition energies of the ISBTs were measured as ω 12 = 124 meV, ω 23 = 185 meV, implying ω 13 = 309 meV [19]. The corresponding transition dipoles were calculated as d 12 = 2.335 nm, d 23 = 2.341 nm, and d 13 = 0.120 nm [21]. So the synthesized 3 level cascade electronic system of ISBTs in such SQW forms a familiar ladder configuration, as shown in Fig. 1. The equivalent 3 level loop "atom" system simu lated in our work is mainly based on the above reported SQW sample. In such a 3 level system, the parity of level |1〉 is set to be opposite to those of the levels |2〉Large and tunable negative refractive index (NRI) via electromagnetically induced chirality is demonstrated in a semiconductor quantum wells (SQWs) nanostructure by using the reported experimental parameters in J.F. Dynes et al., Phys. Rev. Lett. 94, 157403 (2005). It is found: the large and controllable NRI with alterable frequency regions is obtained when the coupling laser field and the relative phase are modulated, which will increase the flexibility and possibility of implementing NRI in the SQWs nanostructure. The scheme rooted in the experimental results may lead a new avenue to NRI material in solid state nanostructure. Fig. 1. Schematic diagr...

An approach for two-dimensional (2D) negative permeability in a Λ-type three-level atomic system interacting with a magnetic probe and the superposition of two orthogonal standing-wave fields is proposed. Through theoretical analysis and numerical simulation, two equally and tunable peak maxima of negative magnetic responses are observed in the x-y plane, and around the peak maxima region the negative permeability is isotropic. A new avenue to 2D isotropic negative permeability in isotropic applications, via the quantum optics method, is achieved in our scheme.