Neutron capture cross section and capture -ray spectrum of Sr in the stellar nucleosynthesis energy region

Katabuchi, Tatsuya*; Igashira, Masayuki*; Kamada, So*; Tajika, Michihide*; Iwamoto, Nobuyuki; Kawano, Toshihiko*

Physical Review C, 108(3), p.034610_1 - 034610_12, 2023/09

https://doi.org/10.1103/PhysRevC.108.034610

Element-specific insight into ferromagnetic stability in UCoGe revealed by soft X-ray magnetic circular dichroism

Takeda, Yukiharu; Pospil, J.*; Yamagami, Hiroshi; Yamamoto, Etsuji; Haga, Yoshinori

Physical Review B, 108(8), p.085129_1 - 085129_10, 2023/08

https://doi.org/10.1103/PhysRevB.108.085129

DC transport in a dissipative superconducting quantum point contact

Visuri, A.-M.*; Mohan, J.*; Uchino, Shun; Huang, M.-Z.*; Esslinger, T.*; Giamarchi, T.*

Physical Review Research (Internet), 5(3), p.033095_1 - 033095_11, 2023/08

https://doi.org/10.1103/PhysRevResearch.5.033095

We study the current-voltage characteristics of a superconducting junction with particle losses at the contacts. We adopt the Keldysh formalism to compute the steady-state current for varying transmission of the contact. In the low transmission regime, the dissipation leads to an enhancement of the current at low bias, a nonmonotonic dependence of current on dissipation, and the emergence of new structures in the current-voltage curves. The effect of dissipation by particle loss is found to be qualitatively different from that of a finite temperature and a finite inelastic scattering rate in the reservoirs.

Measurement of the spatial polarization distribution of circularly polarized gamma rays produced by inverse Compton scattering

Taira, Yoshitaka*; Endo, Shunsuke; Kawamura, Shiori*; Nambu, Taro*; Okuizumi, Mao*; Shizuma, Toshiyuki*; Omer, M.; Zen, H.*; Okano, Yasuaki*; Kitaguchi, Masaaki*

Physical Review A, 107(6), p.063503_1 - 063503_10, 2023/06

https://doi.org/10.1103/PhysRevA.107.063503

no abstracts in English

Dynamic interaction between dislocations and obstacles in BCC iron based on atomic potentials derived using neural networks

Mori, Hideki*; Tsuru, Tomohito; Okumura, Masahiko; Matsunaka, Daisuke*; Shiihara, Yoshinori*; Itakura, Mitsuhiro

Physical Review Materials (Internet), 7(6), p.063605_1 - 063605_8, 2023/06

https://doi.org/10.1103/PhysRevMaterials.7.063605

The introduction of obstacles (e.g., precipitates) for controlling dislocation motion in molecular structures is a prevalent method for designing the mechanical strength of metals. Owing to the nanoscale size of the dislocation core ( 1 nm), atomic modeling is required to investigate the interactions between the dislocation and obstacles. However, conventional empirical potentials are not adequately accurate, in contrast to the calculations based on density functional theory (DFT). Therefore, the atomic-level details of the interactions between the dislocations and obstacles remain unclarified. To this end, this study applied an artificial neural network (ANN) framework to construct an atomic potential by leveraging the high accuracy of DFT. Using the constructed ANN potential, we investigated the dynamic interaction between the edge dislocation and obstacles in BCC iron. When the dislocation crossed the void, an ultrasmooth and symmetric half-loop was observed for the bowing-out dislocation. Except for the screw dislocation, the Peierls stress of all the dislocations predicted using the ANN was less than 100 MPa. More importantly, the results confirmed the formation of an Orowan loop in the interaction between a rigid sphere and dislocation. Furthermore, we discovered a phenomenon in which the Orowan loop disintegrated into two small loops during its interaction with the rigid sphere and dislocation.

Magnon dynamics in a Skyrmion-textured domain wall of antiferromagnets

Lee, S.*; Nakata, Koki; Tchernyshyov, O.*; Kim, S. K.*

Physical Review B, 107(18), p.184432_1 - 184432_12, 2023/05

https://doi.org/10.1103/PhysRevB.107.184432

We theoretically investigate the interaction between magnons and a Skyrmion-textured domain wall in a two-dimensional antiferromagnet and elucidate the resultant properties of magnon transport. Using supersymmetric quantum mechanics, we solve the scattering problem of magnons on top of the domain wall and obtain the exact solutions of propagating and bound magnon modes. Then, we find their properties of reflection and refraction in the Skyrmion-textured domain wall, where magnons experience an emergent magnetic field due to its non-trivial spin texture-induced effective gauge field. Finally, we show that the thermal transport decreases as the domain wall's chirality increases. Our results suggest that the thermal transport of an antiferromagnet is tunable by modulating the Skyrmion charge density of the domain wall.

Nuclear many-body effects on particle emission following muon capture on Si and Ca

Minato, Futoshi; Naito, Tomoya*; Iwamoto, Osamu

Physical Review C, 107(5), p.054314_1 - 054314_10, 2023/05

https://doi.org/10.1103/PhysRevC.107.054314

Effective polarization in proton-induced knockout reactions

Edagawa, Tomoatsu*; Yoshida, Kazuki; Chazono, Yoshiki*; Ogata, Kazuyuki*

Physical Review C, 107(5), p.054603_1 - 054603_7, 2023/05

https://doi.org/10.1103/PhysRevC.107.054603

The effective polarization of the residual nucleus in the proton-induced knockout reaction is investigated within the distorted wave impulse approximation framework. The strong absorption of the emitted particle results in strong selectivity on the reaction "position" depending on the third component of the single-particle orbital angular momentum of the particle inside a nucleus, hence on the spin direction of the reaction residue.

Superfluid signatures in a dissipative quantum point contact

Huang, M.-Z.*; Mohan, J.*; Visuri, A.-M.*; Fabritius, P.*; Talebi, M.*; Wili, S.*; Uchino, Shun; Giamarchi, T.*; Esslinger, T.*

Physical Review Letters, 130(20), p.200404_1 - 200404_8, 2023/05

https://doi.org/10.1103/PhysRevLett.130.200404

We measure superfluid transport of strongly-interacting fermionic lithium atoms through a quantum point contact with local, spin-dependent particle loss. We observe that the characteristic non-Ohmic superfluid transport enabled by high-order multiple Andreev reflections transitions into an excess Ohmic current as the dissipation strength exceeds the superfluid gap. We develop a model with mean-field reservoirs connected via tunneling to a dissipative site. Our calculations in the Keldysh formalism reproduce the observed non-equilibrium particle current, yet do not fully explain the observed loss rate or spin current.

Strong decays of singly heavy baryons from a chiral effective theory of diquarks

Kim, Y.*; Oka, Makoto; Suenaga, Daiki*; Suzuki, Kei

Physical Review D, 107(7), p.074015_1 - 074015_15, 2023/04

https://doi.org/10.1103/PhysRevD.107.074015

A chiral effective theory of scalar and vector diquarks is formulated, which is based on chiral symmetry and includes interactions between scalar and vector diquarks with one or two mesons. We find that the diquark interaction term with two mesons breaks the and flavor symmetries. To determine the coupling constants of the interaction Lagrangians, we investigate one-pion emission decays of singly heavy baryons (, and , , ), where baryons are regarded as diquark-heavy-quark two-body systems. Using this model, we present predictions of the unobserved decay widths of singly heavy baryons. We also study the change of masses and strong decay widths of singly heavy baryons under partial restoration of chiral symmetry.