CiteULike: norris Qiu http://www.citeulike.org/user/norris/author/Qiu CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/norris/article/2582813 <i>Physical Review Letters, Vol. 99, No. 9. (2007)</i><br /><br />We report a metamaterial which simultaneously possesses a negative bulk modulus and mass density. This metamaterial is a zinc blende structure consisting of one fcc array of bubble-contained-water spheres (BWSs) and another relatively shifted fcc array of rubber-coated-gold spheres (RGSs) in epoxy matrix. The negative bulk modulus and mass density are simultaneously derived from the coexistent monopolar resonances from the embedded BWSs and dipolar resonances from the embedded RGSs. The Poisson ratio of the metamaterial also turns negative near the resonance frequency. Metamaterial with Simultaneously Negative Bulk Modulus and Mass Density Yiqun Ding Zhengyou Liu Chunyin Qiu Jing Shi doi:10.1103/PhysRevLett.99.093904 Physical Review Letters, Vol. 99, No. 9. (2007) 2008-03-24T21:17:37-00:00 Physical Review Letters 99 9 APS metamaterial http://www.citeulike.org/user/norris/article/2329489 <i>Opt. Express, Vol. 15, No. 26. (24 December 2007), pp. 17772-17782.</i><br /><br />The previously reported simplified cylindrical linear cloak is improved so that the cloak’s outer surface is impedance-matched to free space. The scattering characteristics of the improved linear cloak is compared to the previous counterpart as well as the recently proposed simplified quadratic cloak derived from quadratic coordinate transformation. Significant improvement in invisibility performance is noticed for the improved linear cloak with respect to the previously proposed linear one. The improved linear cloak and the simplified quadratic cloak have comparable invisibility performances, except that the latter however has to fulfill a minimum shell thickness requirement (i.e. outer radius must be larger than twice of inner radius). When a thin cloak shell is desired, the improved linear cloak is much more superior than the other two versions of simplified cloaks. Scattering characteristics of simplified cylindrical invisibility cloaks Min Yan Zhichao Ruan Min Qiu Opt. Express, Vol. 15, No. 26. (24 December 2007), pp. 17772-17782. 2008-02-04T13:23:34-00:00 Opt. Express 15 26 17772 17782 OSA cloaking metamaterial http://www.citeulike.org/user/norris/article/2185551 <i>Physical Review Letters, Vol. 99, No. 11. (2007)</i><br /><br />A cylindrical wave expansion method is developed to obtain the scattering field for an ideal two-dimensional cylindrical invisibility cloak. A near-ideal model of the invisibility cloak is set up to solve the boundary problem at the inner boundary of the cloak shell. We confirm that a cloak with the ideal material parameters is a perfect invisibility cloak by systematically studying the change of the scattering coefficients from the near-ideal case to the ideal one. However, because of the slow convergence of the zeroth-order scattering coefficients, a tiny perturbation on the cloak would induce a noticeable field scattering and penetration. Ideal Cylindrical Cloak: Perfect but Sensitive to Tiny Perturbations Zhichao Ruan Min Yan Curtis Neff Min Qiu doi:10.1103/PhysRevLett.99.113903 Physical Review Letters, Vol. 99, No. 11. (2007) 2008-01-01T16:44:37-00:00 Physical Review Letters 99 11 APS cloaking metamaterial