Journal Article

Electromagnetically induced transparency with resonant nuclei in a cavity

Sahoo, Balaram, Schlage, Kai, Röhlsberger, Ralf, Wille, Hans-Christian

2012

Overview

Electromagnetically induced transparency is achieved with hard X-rays in a two-level system, using cooperative emission from ensembles of iron-57 nuclei in a special geometry in a low-finesse cavity. A new waveband of transparency Electromagnetically induced transparency (EIT) is a technique in which quantum interference of multi-level atoms renders an otherwise opaque medium transparent for light of a particular wavelength. With the advent of accelerator-driven light sources, there is growing interest in extending the techniques of such optical quantum control to the X-ray regime. Röhlsberger et al . have now identified an alternative EIT mechanism that enables them to demonstrate the phenomenon in the regime of hard X-rays, using an ensemble of iron-57 nuclei. The authors conclude that this type of EIT and its applications could be transferred to the nuclear regime, opening up the field of nuclear quantum optics. The manipulation of light–matter interactions by quantum control of atomic levels has had a profound impact on optical sciences. Such manipulation has many applications, including nonlinear optics at the few-photon level 1 , 2 , 3 , slow light 4 , 5 , lasing without inversion 6 , 7 , 8 and optical quantum information processing 9 , 10 . The critical underlying technique is electromagnetically induced transparency, in which quantum interference between transitions in multilevel atoms 11 , 12 , 13 , 14 , 15 renders an opaque medium transparent near an atomic resonance. With the advent of high-brilliance, accelerator-driven light sources such as storage rings or X-ray lasers, it has become attractive to extend the techniques of optical quantum control to the X-ray regime 16 , 17 . Here we demonstrate electromagnetically induced transparency in the regime of hard X-rays, using the 14.4-kiloelectronvolt nuclear resonance of the Mössbauer isotope iron-57 (a two-level system). We exploit cooperative emission from ensembles of the nuclei, which are embedded in a low-finesse cavity and excited by synchrotron radiation. The spatial modulation of the photonic density of states in a cavity mode leads to the coexistence of superradiant and subradiant states of nuclei, respectively located at an antinode and a node of the cavity field. This scheme causes the nuclei to behave as effective three-level systems, with two degenerate levels in the excited state (one of which can be considered metastable). The radiative coupling of the nuclear ensembles by the cavity field establishes the atomic coherence necessary for the cancellation of resonant absorption. Because this technique does not require atomic systems with a metastable level, electromagnetically induced transparency and its applications can be transferred to the regime of nuclear resonances, establishing the field of nuclear quantum optics.

• Publisher: Nature Publishing Group UK,Nature Publishing Group
• Subject: 639/766/400/482 / Classical and quantum physics: mechanics and fields / Cooperative phenomena; superradiance and superfluorescence / Effects of atomic coherence on propagation, absorption and amplification of light / Electromagnetic interactions / Exact sciences and technology / Excitation / Fundamental areas of phenomenology (including applications) / Holes / Humanities and Social Sciences / Influence / Inversions / Lasers / letter / Light sources / Magnetic properties / Modulation / multidisciplinary / Nuclei / Nuclides / Optical data processing / Optics / Physics / Propagation / Quantum dots / Quantum information / Quantum optics / Resonance / Science / Science (multidisciplinary) / Transparency / X- and γ-ray lasers / X-ray lasers / X-rays