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Applications of negative index materials (NIM) presently are severely limited by absorption. Next to improvements of metamaterial designs, it has been suggested that dense gases of atoms could form a NIM with negligible losses. In such gases, the low absorption is facilitated by quantum interference. Here, we show that additional gain mechanisms can be used to tune and effectively remove absorption in a dense gas NIM. In our setup, the atoms are coherently prepared by control laser fields, and further driven by a weak incoherent pump field to induce gain. We employ nonlinear optical Bloch equations to analyze the optical response. Metastable Neon is identified as a suitable experimental candidate at infrared frequencies to implement a lossless active negative index material.
We show that a gas of relativistic electrons is a left-handed material at low frequencies by computing the effective electric permittivity and effective magnetic permeability that appear in Maxwells equations in terms of the responses appearing in th
In this paper we consider a two-dimensional metamaterial comprising an array of qubits (two level quantum objects). Here we show that a two-dimensional quantum metamaterial may be controlled, e.g. via the application of a magnetic flux, so as to prov
We investigate the dispersion of a classical electromagnetic field in a relativistic ideal gas of charged bosons using scalar quantum electrodynamics at finite temperature and charge density. We derive the effective electromagnetic responses and the
Light is known to exert a pushing force through the radiation pressure on any surface it is incident upon, via the transfer of momentum from the light to the surface. For an atom, the interaction with light can lead to both absorption as well as emis
Strong laser-induced magnetization of oxygen gas at room temperature and atmospheric pressure is achieved experimentally on the sub-nanosecond time scale. The method is based on controlling the electronic spin of paramagnetic molecules by means of ma