Unextendible product basis for fermionic systems
Abstract
We discuss the concept of unextendible product basis (UPB) and generalized UPB for fermionic systems, using Slater determinants as an analogue of product states, in the antisymmetric subspace $\wedge^ N \bC^M$. We construct an explicit example of generalized fermionic unextendible product basis (FUPB) of minimum cardinality $N(MN)+1$ for any $N\ge2,M\ge4$. We also show that any bipartite antisymmetric space $\wedge^ 2 \bC^M$ of codimension two is spanned by Slater determinants, and the spaces of higher codimension may not be spanned by Slater determinants. Furthermore, we construct an example of complex FUPB of $N=2,M=4$ with minimum cardinality $5$. In contrast, we show that a real FUPB does not exist for $N=2,M=4$ . Finally we provide a systematic construction for FUPBs of higher dimensions using FUPBs and UPBs of lower dimensions.
 Publication:

Journal of Mathematical Physics
 Pub Date:
 August 2014
 DOI:
 10.1063/1.4893358
 arXiv:
 arXiv:1312.4218
 Bibcode:
 2014JMP....55h2207C
 Keywords:

 Quantum Physics
 EPrint:
 17 pages, no figure. Comments are welcome