Physics – Quantum Physics
Scientific paper
2009-05-14
Physics
Quantum Physics
67 pages, approximately 6 gazillion figures. v2 has new results proving hardness for reflection-invariant quantum and classica
Scientific paper
We study the complexity of a class of problems involving satisfying constraints which remain the same under translations in one or more spatial directions. In this paper, we show hardness of a classical tiling problem on an N x N 2-dimensional grid and a quantum problem involving finding the ground state energy of a 1-dimensional quantum system of N particles. In both cases, the only input is N, provided in binary. We show that the classical problem is NEXP-complete and the quantum problem is QMA_EXP-complete. Thus, an algorithm for these problems which runs in time polynomial in N (exponential in the input size) would imply that EXP = NEXP or BQEXP = QMA_EXP, respectively. Although tiling in general is already known to be NEXP-complete, to our knowledge, all previous reductions require that either the set of tiles and their constraints or some varying boundary conditions be given as part of the input. In the problem considered here, these are fixed, constant-sized parameters of the problem. Instead, the problem instance is encoded solely in the size of the system.
Gottesman Daniel
Irani Sandy
No associations
LandOfFree
The Quantum and Classical Complexity of Translationally Invariant Tiling and Hamiltonian Problems does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The Quantum and Classical Complexity of Translationally Invariant Tiling and Hamiltonian Problems, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Quantum and Classical Complexity of Translationally Invariant Tiling and Hamiltonian Problems will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-523400