{ "id": "1105.0391", "version": "v1", "published": "2011-05-02T18:07:22.000Z", "updated": "2011-05-02T18:07:22.000Z", "title": "From a Particle in a Box to the Uncertainty Relation in a Quantum Dot and to Reflecting Walls for Relativistic Fermions", "authors": [ "M. H. Al-Hashimi", "U. -J. Wiese" ], "comment": "36 pages, 5 figures", "journal": "Annals of Physics 327 (2012) 2742-2759", "categories": [ "quant-ph", "hep-th", "math-ph", "math.MP" ], "abstract": "We consider a 1-parameter family of self-adjoint extensions of the Hamiltonian for a particle confined to a finite interval with perfectly reflecting boundary conditions. In some cases, one obtains negative energy states which seems to violate the Heisenberg uncertainty relation. We use this as a motivation to derive a generalized uncertainty relation valid for an arbitrarily shaped quantum dot with general perfectly reflecting walls in $d$ dimensions. In addition, a general uncertainty relation for non-Hermitean operators is derived and applied to the non-Hermitean momentum operator in a quantum dot. We also consider minimal uncertainty wave packets in this situation, and we prove that the spectrum depends monotonically on the self-adjoint extension parameter. In addition, we construct the most general boundary conditions for semiconductor heterostructures such as quantum dots, quantum wires, and quantum wells, which are characterized by a 4-parameter family of self-adjoint extensions. Finally, we consider perfectly reflecting boundary conditions for relativistic fermions confined to a finite volume or localized on a domain wall, which are characterized by a 1-parameter family of self-adjoint extensions in the $(1+1)$-d and $(2+1)$-d cases, and by a 4-parameter family in the $(3+1)$-d and $(4+1)$-d cases.", "revisions": [ { "version": "v1", "updated": "2011-05-02T18:07:22.000Z" } ], "analyses": { "keywords": [ "uncertainty relation", "quantum dot", "relativistic fermions", "reflecting walls", "self-adjoint extension" ], "tags": [ "journal article" ], "publication": { "doi": "10.1016/j.aop.2011.05.003", "journal": "Annals of Physics", "year": 2012, "month": "Jan", "volume": 327, "number": 1, "pages": 1 }, "note": { "typesetting": "TeX", "pages": 36, "language": "en", "license": "arXiv", "status": "editable", "inspire": 898696, "adsabs": "2012AnPhy.327....1A" } } }