Interference of identical particles from entanglement to boson-sampling

• Published in: Journal of physics. B, Atomic, molecular, and optical physics Atomic, molecular, and optical physics, 2014-05, Vol.47 (10), p.1-34
• Main Author: Tichy, Malte C
• Format: Article
• Language: English
• Subjects: Bosons; Coherence; Dynamics; Fermions; Indicators; Interference; Particles (of physics); Quantum computing
• ISSN: 0953-4075; 1361-6455
• DOI: 10.1088/0953-4075147/10/103001

Progress in the reliable preparation, coherent propagation and efficient detection of many-body states has recently brought collective quantum phenomena of many identical particles into the spotlight. This tutorial introduces the physics of many-boson and many-fermion interference required for the description of current experiments and for the understanding of novel approaches to quantum computing. The field is motivated via the two-particle case, for which the uncorrelated, classical dynamics of distinguishable particles is compared to the quantum behaviour of identical bosons and fermions. The realms of indistinguishable and distinguishable particles are connected by a monotonic transition, on a scale defined by the coherence length of the interfering particles. Finally, the quantum-to-classical transition between many indistinguishable and many distinguishable particles features non-monotonic structures, which dismisses the single-particle coherence length as unique indicator for interference capability. While the same physical principles govern small and large systems, the deployment of the intrinsic complexity of collective many-body interference makes more particles behave differently.