From a five-dimensional Minkowski view the five-dimensional angular momentum of a free spin-O particle moving in de Sifter spacefime is conservative, by which its fimelike geodesics can be labeled completely and uniqu...From a five-dimensional Minkowski view the five-dimensional angular momentum of a free spin-O particle moving in de Sifter spacefime is conservative, by which its fimelike geodesics can be labeled completely and uniquely. Based on that observation and working in Belframi coordinate for de Sifter spacefime, solutions and their asymptotic behavior to the Belframi-de Sifter-Klein-Gordon equation are given.展开更多
We use neutron powder diffraction to study the non-superconducting phases of ThFeAsN1-xOx with x = 0.15,0.6.In our previous results of the superconducting phase ThFeAsN with Tc = 30 K,no magnetic transition is observe...We use neutron powder diffraction to study the non-superconducting phases of ThFeAsN1-xOx with x = 0.15,0.6.In our previous results of the superconducting phase ThFeAsN with Tc = 30 K,no magnetic transition is observed by cooling down to 6 K,and possible oxygen occupancy at the nitrogen site is shown in the refinement[Europhys.Lett.117(2017)57005].Here in the oxygen doped system ThFeAsN1-xOx,two superconducting regions(0≤x≤0.1 and 0.25≤x≤0.55)are identified by transport experiments[J.Phys.:Condens.Matter30(2018)255602].However,within the resolution of our neutron powder diffraction experiment,neither the intermediate doping x= 0.15 nor the heavily overdoped compound x = 0.6 shows any magnetic order from 300 K to 4 K.Therefore,while it shares the common phenomenon of two superconducting domes as most 1111-type iron-based superconductors,the magneticall.y ordered parent compound may not exist in this nitride family.展开更多
We conducted a comparative study of the magnetic and transport properties of single-crystalline LaCo_(2)As_(2) and NdCo_(2)As_(2).LaCo_(2)As_(2) is a soft metallic ferromagnet which exhibits purely intrinsic anomalous...We conducted a comparative study of the magnetic and transport properties of single-crystalline LaCo_(2)As_(2) and NdCo_(2)As_(2).LaCo_(2)As_(2) is a soft metallic ferromagnet which exhibits purely intrinsic anomalous Hall effect(AHE) due to Co-3d electrons. With Nd-4f electronic magnetism, ferrimagnetic NdCo_(2)As_(2) manifests pronounced sign reversal and multiple hysteresis loops in temperature-and field-dependent magnetization, Hall resistivity, and magnetoresistance, due to complicated magnetic structural changes. We reveal that the AHE for NdCo_(2)As_(2) is stemming from the Co sub-lattice and deduce its phase diagram which includes magnetic compensation and two meta-magnetic phase transitions. The sensitivity of the Hall effect on the details of the magnetic structures in ferrimagnetic NdCo_(2)As_(2) provides a unique opportunity to explore the magnetic interaction between 4f and 3d electrons and its impact on the electronic structure.展开更多
基金The project supported by National Natural Science Foundation of China under Grant No.10547002
文摘From a five-dimensional Minkowski view the five-dimensional angular momentum of a free spin-O particle moving in de Sifter spacefime is conservative, by which its fimelike geodesics can be labeled completely and uniquely. Based on that observation and working in Belframi coordinate for de Sifter spacefime, solutions and their asymptotic behavior to the Belframi-de Sifter-Klein-Gordon equation are given.
基金Supported by the Strategic Priority Research Program of Chinese Academy of Sciences under Grant Nos XDB07020300and XDB25000000the National Key Research and Development Program of China under Grant Nos 2017YFA0303103,2017YFA0302903 and 2016YFA0300502+3 种基金the National Natural Science Foundation of China under Grant Nos 11374011,11504347,11304183,11674406 and 11822411the Youth Innovation Promotion Association of Chinese Academy of Sciences under Grant No2016004the Key Laboratory of Neutron Physics of CAEP under Grant No 2015AB03the Science Challenge Project under Grant No TZ2016004
文摘We use neutron powder diffraction to study the non-superconducting phases of ThFeAsN1-xOx with x = 0.15,0.6.In our previous results of the superconducting phase ThFeAsN with Tc = 30 K,no magnetic transition is observed by cooling down to 6 K,and possible oxygen occupancy at the nitrogen site is shown in the refinement[Europhys.Lett.117(2017)57005].Here in the oxygen doped system ThFeAsN1-xOx,two superconducting regions(0≤x≤0.1 and 0.25≤x≤0.55)are identified by transport experiments[J.Phys.:Condens.Matter30(2018)255602].However,within the resolution of our neutron powder diffraction experiment,neither the intermediate doping x= 0.15 nor the heavily overdoped compound x = 0.6 shows any magnetic order from 300 K to 4 K.Therefore,while it shares the common phenomenon of two superconducting domes as most 1111-type iron-based superconductors,the magneticall.y ordered parent compound may not exist in this nitride family.
基金Project supported by the National Key Research and Development Program of China(Grant No.2018YFB1502502)the National Natural Science Foundation of China(Grant Nos.12141002 and 12225401)+6 种基金the Fund from Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratorysupported by the Interdisciplinary Program of Wuhan National High Magnetic Field Center(Grant No.WHMFC202123)Huazhong University of Science and Technologysupported by the National Natural Science Foundation of China(Grant Nos.12074041 and 11674030)the Foundation of the National Key Laboratory of Shock Wave and Detonation Physics(Grant No.6142A03191005)the National Key Research and Development Program of China(Grant No.2016YFA0302300)the startup funding of Beijing Normal University。
文摘We conducted a comparative study of the magnetic and transport properties of single-crystalline LaCo_(2)As_(2) and NdCo_(2)As_(2).LaCo_(2)As_(2) is a soft metallic ferromagnet which exhibits purely intrinsic anomalous Hall effect(AHE) due to Co-3d electrons. With Nd-4f electronic magnetism, ferrimagnetic NdCo_(2)As_(2) manifests pronounced sign reversal and multiple hysteresis loops in temperature-and field-dependent magnetization, Hall resistivity, and magnetoresistance, due to complicated magnetic structural changes. We reveal that the AHE for NdCo_(2)As_(2) is stemming from the Co sub-lattice and deduce its phase diagram which includes magnetic compensation and two meta-magnetic phase transitions. The sensitivity of the Hall effect on the details of the magnetic structures in ferrimagnetic NdCo_(2)As_(2) provides a unique opportunity to explore the magnetic interaction between 4f and 3d electrons and its impact on the electronic structure.
