4 papers · 1 filter
Two-dimensional quantum central limit theorem by quantum walks
Keisuke Asahara, Daiju Funakawa, Motoki Seki +1
The weak limit theorem (WLT), the quantum analogue of the central limit theorem, is foundational to quantum walk (QW) theory. Unlike the universal Gaussian limit of classical walks…
Spectral mapping theorem of an abstract non-unitary quantum walk
Keisuke Asahara, Daiju Funakawa, Etsuo Segawa +2
This paper continues the previous work (Quantum Inf. Process (2019)) by two authors of the present paper about a spectral mapping property of chiral symmetric unitary operators. In…
The Witten Index for One-dimensional Non-unitary Quantum Walks with Gapless Time-evolution
Keisuke Asahara, Daiju Funakawa, Motoki Seki +1
Recent developments in the index theory of discrete-time quantum walks allow us to assign a certain well-defined supersymmetric index to a pair of a unitary time-evolution and…
Spectral analysis of an abstract pair interaction model
Keisuke Asahara, Daiju Funakawa
We consider an abstract pair-interaction model in quantum field theory with a coupling constant and analyze the Hamiltonian of the model. In the massive c…