AAPPS Bulletin最新文献

In this paper, we review and discuss the main properties of the time-reversal operator T and its action in classical electromagnetism and in quantum mechanics. In particular, we discuss the relation (and differences) between time-reversal invariance and reciprocity.

As a hypothetic particle, a sterile neutrino can exist in types of new physics models. In this work by investigating flavor violating semileptonic and leptonic decays of K,D, and B mesons induced by the GeV scale sterile neutrino, we explore its allowed regions in parameter space. Analytically, we derive branching fractions of semileptonic decay (M^{+}_{h}to M_{l}^{+}ell _{1}^{+}ell _{2}^{-}) and leptonic decay (M^{0}to ell _{1}^{-}ell _{2}^{+}), including the contribution from a new box diagram contribution due to the massive sterile neutrino. Imposing its mass ranges, we numerically analyze the active-sterile neutrino mixings in corresponding regions. We find that when the sterile neutrino mass is located in between pion and kaon mass, K⁺→π⁺e^±μ^∓ gives the strongest constraint while B⁺→π⁺e^±μ^∓ provides the dominated constraint when its mass in between of kaon and B meson. If the sterile neutrino is even heavier than Bmesons, the LHCb (B^{0}_{s}to mu ^{pm } e^{mp }) results gives the strongest constraint.

In this article, we review the recent progress of the scanning tunneling microscopy studies of 1T-TaS₂ and 1T-TaSe₂ for bulk single crystals and molecular beam epitaxy monolayer films. We focus on how to understand the Mott insulating state in the whole set of materials, even when the stacking order takes effect. Based on this understanding, we discuss tuning the Mott insulator to a metallic state with different techniques, with Mott physics information revealed from the tuning process. The Kondo physics and quantum spin liquid state of 1T-TaS₂ and 1T-TaSe₂ are further discussed. This good platform of strong correlation must bring more intriguing phenomenon and physics in the future.

Although the multimessenger detection of the neutron star merger event GW170817 confirmed that mergers are promising sites producing the majority of nature’s heavy elements via the rapid neutron-capture process (r-process), a number of issues related to the production of translead nuclei—the actinides—remain to be answered. In this short review paper, we summarize the general requirements for actinide production in r-process and the impact of nuclear physics inputs. We also discuss recent efforts addressing the actinide production in neutron star mergers from different perspectives, including signatures that may be probed by future kilonova and γ-ray observations, the abundance scattering in metal-poor stars, and constraints put by the presence of short-lived radioactive actinides in the Solar system.

This review introduces the technique of helium ion microscopy along with some unique applications of this technology in the fields of electronics and biology, as performed at the National Institute of Advanced Industrial Science and Technology, Japan, over the last several years. Observations of large-scale integrated circuits, analyses of low-dielectric-constant films with minimal damage, and assessments of copper metal in insulating films are discussed. The special characteristics of this technique are explained, including low-energy input to the material and minimal secondary electron energy resulting from helium ion irradiation. Applications to electronic materials, such as tuning the electrical conductivity of graphene films by helium ion beam irradiation and the formation of nanopore arrays on graphene films with nanometer-scale control, are presented. The use of helium ion microscopy to examine cellular tissues based on the low damage imparted by the ion beam is also evaluated.

Quantum incompatibility is a fundamental property in quantum physics and is considered as a resource in quantum information processing tasks. Here, we construct a framework based on the incompatibility witness originated from quantum state discrimination. In this framework, we discuss the geometrical properties of the witnesses with noisy mutually unbiased bases and construct a quantifier of quantum incompatibility associated with geometrical information. Furthermore, we explore the incompatibility of a pair of positive operator valued measurements, which only depends on the information of measurements, and discuss the incompatibility of measurements which can be discriminated by mutually unbiased bases. Finally, if we take a resource-theory perspective, the new-defined quantifier can characterize the resource of incompatibility. This geometrical framework gives the evidence that vectors can be utilized to describe resourceful incompatibility and make a step to explore geometrical features of quantum resources.

The X-ray Free Electron Laser of Pohang Accelerator Laboratory (PAL-XFEL) was opened for the user in 2017. PAL-XFEL was the third XFEL facility in the world and well known for the small timing jitter of FEL radiation. This success was possible because of the significant achievements in the accelerator technology in PAL-XFEL. They are not limited to a small part of the accelerator but cover from the injector for the electron beam generation to the undulator line for FEL radiation. In this review, we describe the details of newly developed devices that contributed to the successful construction of PAL-XFEL.

Nuclear theory research is undergoing a renaissance owing to the recent advancements in the high-performance computing. As nucleus is a quantum many-body system with complicated interparticle interactions, initial theoretical developments were predominantly based on different phenomenological models derived with the help of numerous simplifying assumptions. Although appropriate nuclear many-body theories were formulated, these were hardly adopted in practical applications because of computational limitations. However, since the last decade, this scenario has changed as a result of rapid improvements in the computational power and the associated numerical techniques. Realistic microscopic theories with superior predictive power are now routinely used even for systems which are far beyond the laboratory reach. This review discusses recent achievements in the microscopic theories of large amplitude nuclear dynamics. Particularly, after a succinct historical introduction, emphasis is given to the discussions on the microscopic modelling of nuclear fission dynamics. Also, related future directions are mentioned in brief.