The random mass Dirac model and long-range correlations on an integrated optical platform

• Published in: Nature communications 2013-01, Vol.4 (1), p.1368-1368, Article 1368
• Main Authors: Keil, Robert, Zeuner, Julia M., Dreisow, Felix, Heinrich, Matthias, Tünnermann, Andreas, Nolte, Stefan, Szameit, Alexander
• Format: Article
• Language: English
• Subjects: 639/301/119; 639/766/25; 639/766/400; Humanities and Social Sciences; multidisciplinary; Phase transitions; Photonics; Physics; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms2384

Long-range correlation—the non-local interdependence of distant events—is a crucial feature in many natural and artificial environments. In the context of solid state physics, impurity spins in doped spin chains and ladders with antiferromagnetic interaction are a prominent manifestation of this phenomenon, which is the physical origin of the unusual magnetic and thermodynamic properties of these materials. It turns out that such systems are described by a one-dimensional Dirac equation for a relativistic fermion with random mass. Here we present an optical configuration, which implements this one-dimensional random mass Dirac equation on a chip. On this platform, we provide a miniaturized optical test-bed for the physics of Dirac fermions with variable mass, as well as of antiferromagnetic spin systems. Moreover, our data suggest the occurence of long-range correlations in an integrated optical device, despite the exclusively short-ranged interactions between the constituting channels. Photonic lattices provide a useful platform for simulating quantum dynamics and systems. Keil et al. fabricate coupled waveguides on-chip and use them to simulate the one-dimensional random mass Dirac model, a test-bed for both Dirac fermions and antiferromagnetic spin systems.