The discovery of superconductivity in Sr/Ca-doped infinite-layer nickelates Nd(La)NiO_(2)thin films inspired extensive experimental and theoretical research.However,research on the possibilities of enhanced critical t...The discovery of superconductivity in Sr/Ca-doped infinite-layer nickelates Nd(La)NiO_(2)thin films inspired extensive experimental and theoretical research.However,research on the possibilities of enhanced critical temperature by interface heterostructure is still lacking.Due to the similarities of the crystal structure and band structure of infinite-layer nickelate La NiO_(2)and cuprate CaCuO_(2),we investigate the crystal,electronic and magnetic properties of La NiO_(2):CaCuO_(2)heterostructure using density functional theory and dynamical mean-field theory.Our theoretical results demonstrate that,even a very weak inter-layer z-direction bond is formed,an intrinsic charge transfer between Cu-3d_(x^(2)-y^(2))and Ni-3d_((x^(2)-y^(2)))orbitals is obtained.The weak interlayer hopping between Cu and Ni leaves a parallel band contributed by Ni/Cu-3d_((x^(2)-y^(2)))orbitals near the Fermi energy.Such an infinite-layer heterostructure with negligible interlayer interaction and robust charge transfer opens a new way for interface engineering and nickelate superconductors.展开更多
The core structure,Peierls stress and core energy,etc.are comprehensively investigated for the 90°dislocation and the 60°dislocation in metal aluminum using the fully discrete Peierls model,and in particular...The core structure,Peierls stress and core energy,etc.are comprehensively investigated for the 90°dislocation and the 60°dislocation in metal aluminum using the fully discrete Peierls model,and in particular thermal effects are included for temperature range 0≤T≤900 K.For the 90°dislocation,the core clearly dissociates into two partial dislocations with the separating distance D~12?,and the Peierls stress is very smallσp<1 k Pa.The nearly vanishing Peierls stress results from the large characteristic width and a small step length of the 90°dislocation.The 60°dislocation dissociates into 30°and 90°partial dislocations with the separating distance D~11A.The Peierls stress of the 60°dislocation grows up from1 MPa to 2 MPa as the temperature increases from 0 K to 900 K.Temperature influence on the core structures is weak for both the 90°dislocation and the 60°dislocation.The core structures theoretically predicted at T=0 K are also confirmed by the first principle simulations.展开更多
A one-dimensional(1 D) self-organized array composed of dislocation and anti-dislocation is analytically investigated in the frame of Peierls theory. From the exact solution of the Peierls equation, it is found that t...A one-dimensional(1 D) self-organized array composed of dislocation and anti-dislocation is analytically investigated in the frame of Peierls theory. From the exact solution of the Peierls equation, it is found that there exists strong neutralizing effect that makes the Burgers vector of each individual dislocation in the equilibrium array smaller than that of an isolated dislocation. This neutralizing effect is not negligible even though dislocations are well separated. For example, when the distance between the dislocation and the anti-dislocation is as large as ten times of the dislocation width, the actual Burgers vector is only about 80% of an isolated dislocation. The neutralizing effect originates physically from the power-law asymptotic behavior that enables two dislocations interfere even though they are well separated.展开更多
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2021YFA0718900and 2022YFA1403000)the Key Research Program of Frontier Sciences of CAS(Grant No.ZDBS-LY-SLH008)+2 种基金the National Natural Science Foundation of China(Grant Nos.11974365,12004400,and 51931011)the Science Center of the National Natural Science Foundation of China(Grant No.52088101)the K.C.Wong Education Foundation(Grant No.GJTD-2020-11)。
文摘The discovery of superconductivity in Sr/Ca-doped infinite-layer nickelates Nd(La)NiO_(2)thin films inspired extensive experimental and theoretical research.However,research on the possibilities of enhanced critical temperature by interface heterostructure is still lacking.Due to the similarities of the crystal structure and band structure of infinite-layer nickelate La NiO_(2)and cuprate CaCuO_(2),we investigate the crystal,electronic and magnetic properties of La NiO_(2):CaCuO_(2)heterostructure using density functional theory and dynamical mean-field theory.Our theoretical results demonstrate that,even a very weak inter-layer z-direction bond is formed,an intrinsic charge transfer between Cu-3d_(x^(2)-y^(2))and Ni-3d_((x^(2)-y^(2)))orbitals is obtained.The weak interlayer hopping between Cu and Ni leaves a parallel band contributed by Ni/Cu-3d_((x^(2)-y^(2)))orbitals near the Fermi energy.Such an infinite-layer heterostructure with negligible interlayer interaction and robust charge transfer opens a new way for interface engineering and nickelate superconductors.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11874093 and 11974062)。
文摘The core structure,Peierls stress and core energy,etc.are comprehensively investigated for the 90°dislocation and the 60°dislocation in metal aluminum using the fully discrete Peierls model,and in particular thermal effects are included for temperature range 0≤T≤900 K.For the 90°dislocation,the core clearly dissociates into two partial dislocations with the separating distance D~12?,and the Peierls stress is very smallσp<1 k Pa.The nearly vanishing Peierls stress results from the large characteristic width and a small step length of the 90°dislocation.The 60°dislocation dissociates into 30°and 90°partial dislocations with the separating distance D~11A.The Peierls stress of the 60°dislocation grows up from1 MPa to 2 MPa as the temperature increases from 0 K to 900 K.Temperature influence on the core structures is weak for both the 90°dislocation and the 60°dislocation.The core structures theoretically predicted at T=0 K are also confirmed by the first principle simulations.
基金Project supported by the National Natural Science Foundation of China(Grant No.11874093)
文摘A one-dimensional(1 D) self-organized array composed of dislocation and anti-dislocation is analytically investigated in the frame of Peierls theory. From the exact solution of the Peierls equation, it is found that there exists strong neutralizing effect that makes the Burgers vector of each individual dislocation in the equilibrium array smaller than that of an isolated dislocation. This neutralizing effect is not negligible even though dislocations are well separated. For example, when the distance between the dislocation and the anti-dislocation is as large as ten times of the dislocation width, the actual Burgers vector is only about 80% of an isolated dislocation. The neutralizing effect originates physically from the power-law asymptotic behavior that enables two dislocations interfere even though they are well separated.
