2p-Z-1 Hubbard模型の基底状態エネルギーの漸近展開

哲郎 佐宗, 章 小栗

Liqi Wang, Shixin Zhu

In this paper, based on the Steane's enlargement construction, three classes of non-binary quantum codes are constructed from classical repeated-root cyclic codes of length 2ps over 𝔽q with odd characteristic p. The exact minimum distances of these quantum codes are determined. This construction yields a quantum MDS code with parameters [[2p, 2p - 4, 3]]p and two good quantum codes with parameters [[2p, 2p - 7, 4]]p and [[2p, 2p - 10, 5]]p.

健太郎 浦崎, 哲郎 佐宗

Hosaka Koichi, Yutaro Torizuka, Philipp Schmidt +4 more

In this paper, as a continuation of our recent article demonstrating that the 2p atom pair is entangled in the H2 photodissociation [Phys. Rev. A 111, 023116 (2025)], we have discovered the origins of the entanglement for the 2p atom-pair state and obtained the entanglement entropies by origins. The same investigation has been carried out for the precursor molecular state of the 2p atom pair. The reason for the increase of the entanglement entropy during the dissociation from the precursor molecule into the H(2p) + H(2p) atom pair has been made clear.

勝 加藤, 匡寛 和藤

Takeshi Odagiri, Takehiko Tanabe, Noriyuki Kouchi

We have measured the coincidence time spectra of two Lyman-α photons emitted by a pair of H(2p) atoms in the photodissociation of H 2 at the incident photon energy of 33.66 eV and at the hydrogen gas pressures of 0.40 Pa and 0.02 Pa, from which the angular distributions of two Lyman-α photons have been obtained. The experimental angular distributions indicate the generation of the entangled pair of H(2p) atoms as predicted by the theory of our group (Miyagi et al 2007 J. Phys. B 40 617) and the role of a new kind of reaction, i.e. the reaction of the entangled pair of H(2p) atoms with an H 2 molecule that efficiently changes the entanglement. It has turned out that more entangled pairs of H(2p) atoms survive at 0.02 Pa than at 0.40 Pa. The decay time constant in the coincidence time spectrum at 0.02 Pa is approximately half the lifetime of a single H(2p) atom, 1.60 ns, while the decay time constant at 0.40 Pa is in agreement with the lifetime of a single H(2p) atom. It follows that the decay faster than the lifetime of a single H(2p) atom originates from the entanglement in the pair of H(2p) atoms.