提出了一种在金刚石中两个临近氮-空位色心(nitrogen-vacancy color center,简称NV色心)之间施加受控非门(C-NOT gate)的新方案.在该方案中,临近NV色心间的强电偶极耦合将导致态依赖的能级移动,从而施加可控的激光共振激发可以实现快速...提出了一种在金刚石中两个临近氮-空位色心(nitrogen-vacancy color center,简称NV色心)之间施加受控非门(C-NOT gate)的新方案.在该方案中,临近NV色心间的强电偶极耦合将导致态依赖的能级移动,从而施加可控的激光共振激发可以实现快速受控相位门(C-phase gate),结合单比特操作,可以快速实现C-NOT门.在两个相邻10 nm的NV色心之间,C-NOT门操作时间最快可达120 ns,比传统磁偶极方式快了2个量级.为了降低激发态自发辐射的影响,提出利用非共振腔抑制自发辐射.模拟结果显示C-phase门操控保真度可以达到98.88%.最后,将该方案扩展到一维NV色心自旋链.展开更多
By using first principles calculations, four two-dimensional B-C-N ternary sheets with ordered and uniform element distribution are predicted based on the C, B, or N filled g-C3N4 sheet. These B-C-N ternary sheets are...By using first principles calculations, four two-dimensional B-C-N ternary sheets with ordered and uniform element distribution are predicted based on the C, B, or N filled g-C3N4 sheet. These B-C-N ternary sheets are metallic except for B4-C3N4 monolayer, which is a semiconductor with an energy band gap of 1.18 eV. In particular, the BnC-C3N4 is a ferromagnetic metal with a net magnetic moment of 0.57 μB/cell, which can be used to develop metal-free spintronic device. The calculated formation energy indicates these B-C-N ternary sheets are highly thermal stable. It presents a new route to obtain uniform B-C-N ternary sheet for electronic and spintronic applications.展开更多
We report an ultrafast spectroscopy investigation that addresses the subtle location effect in a prototypical semiconductor-MOF hybrid system with TiO2 nanoparticles being incorporated inside or supported onto Cu3(BTC...We report an ultrafast spectroscopy investigation that addresses the subtle location effect in a prototypical semiconductor-MOF hybrid system with TiO2 nanoparticles being incorporated inside or supported onto Cu3(BTC)2,denoted as TiO2@Cu3(BTC)2 and TiO2/Cu3(BTC)2,respectively.By tracking in real time the interface electron dynamics in the hybrid system,we find that the interface states formed between TiO2 and Cu3(BTC)2 can act as an effective relay for electron transfer,whose effciency rests on the relative location of the two components.It is such a subtle location effect that brings on difference in photocatalytic CO2 reduction using the two semiconductor-MOF hybrids.The mechanistic understanding of the involved interface electron-transfer behavior and effect opens a helpful perspective for rational design of MOF-based hybrid systems for photoelectrochemical applications.展开更多
Quantum dots comprise a type of quantum impurity system. The entanglement and co- herence of quantum states are significantly influenced by the strong electron-electron interactions among impurities and their dissipat...Quantum dots comprise a type of quantum impurity system. The entanglement and co- herence of quantum states are significantly influenced by the strong electron-electron interactions among impurities and their dissipative coupling with the surrounding environment. Competition between many-body effects and transfer couplings plays an important role in determining the entanglement among localized impurity spins. In this work, we employ the hierarchical-equations-of-rnotion approach to explore the entanglement of a strongly correlated double quantum dots system. The relation between the total system entropy and those of subsystems is also investigated.展开更多
In view of the high activity of Pt single atoms in the low-temperature oxidation of CO,we investigate the adsorption behavior of Pt single atoms on reduced rutile TiO2(110)surface and their interaction with CO and O2 ...In view of the high activity of Pt single atoms in the low-temperature oxidation of CO,we investigate the adsorption behavior of Pt single atoms on reduced rutile TiO2(110)surface and their interaction with CO and O2 molecules using scanning tunneling microscopy and density function theory calculations.Pt single atoms were prepared on the TiO2(110)surface at 80 K,showing their preferred adsorption sites at the oxygen vacancies.We characterized the adsorption configurations of CO and O2 molecules separately to the TiO2-supported Pt single atom samples at 80 K.It is found that the Pt single atoms tend to capture one CO to form Pt-CO complexes,with the CO molecule bonding to the fivefold coordinated Ti(Ti5 c)atom at the next nearest neighbor site.After annealing the sample from 80 K to 100 K,CO molecules may diffuse,forming another type of complexes,Pt-(CO)2.For O2 adsorption,each Pt single atom may also capture one O2 molecule,forming Pt-O2 complexes with O2 molecule bonding to either the nearest or the next nearest neighboring Ti5c sites.Our study provides the single-molecule-level knowledge of the interaction of CO and O2 with Pt single atoms,which represent the important initial states of the reaction between CO and O2.展开更多
Interfacial properties between perovskite layers and metal electrodes play a crucial role in the device performance and the long-term stability of perovskite solar cells.Here,we report a comprehensive study of the int...Interfacial properties between perovskite layers and metal electrodes play a crucial role in the device performance and the long-term stability of perovskite solar cells.Here,we report a comprehensive study of the interfacial degradation and ion migration at the interface between CH3NH3PbI3 perovskite layer and Ag electrode.Using in situ photoemission spectroscopy measurements,we found that the Ag electrode could induce the degradation of perovskite layers,leading to the formation of PbI2 and AgI species and the reduction of Pb^2+ions to metallic Pb species at the interface.The unconventional enhancement of the intensities of I 3d spectra provides direct experimental evidences for the migration of iodide ions from CH3NH3PbI3 subsurface to Ag electrode.Moreover,the contact of Ag electrode and perovskite layers induces an interfacial dipole of 0.3 eV at CH3NH3PbI3/Ag interfaces,which may further facilitate iodide ion diffusion,resulting in the decomposition of perovskite layers and the corrosion of Ag electrode.展开更多
基金Supported by National Basic Research Program of China(2014 CB643903,2013 CB932904)National Natural Science Foundation of China(61435012,61274125,and 61274013)+1 种基金National Special funds for the Development of Major Research Equipment and Instruments,China(2012YQ140005)Strategic Priority Research Program(B)of Chinese Academy of Sciences(XDB01010200)
基金This work was supported by the National Natural Science Foundation of China(21973086,22203083)the Fundamental Research Funds for the Central Universities(WK2060000018).
基金supported by the National Natural Science Foundation of China(No.21973086,No.22203083)the Ministry of Science and Technology of China(No.2021YFA1200103)the Fundamental Research Funds for the Central Universities(No.WK2060000018)。
基金supported by the National Key R&D Program of China (2017YFA0304800)the National Natural Science Foundation of China (U20A20218, 61525504,61435011)+1 种基金Fundamental Research Funds for the Central Universitiesthe Youth Innovation Promotion Association of C AS(2018490)。
基金National Key Research and Development Program of China(Nos.2018YFA0306600,2017YFA0305000)National Natural Science Foundation of China(Item Numbers:11775209,81788101,11761131011)+2 种基金Anhui Quantum Information Technology Leading Project(Item Number:AHY050000)Fundamental Research Funds for the Central UniversitiesUSTC Research Funds of the Double First-Class Initiative.
文摘提出了一种在金刚石中两个临近氮-空位色心(nitrogen-vacancy color center,简称NV色心)之间施加受控非门(C-NOT gate)的新方案.在该方案中,临近NV色心间的强电偶极耦合将导致态依赖的能级移动,从而施加可控的激光共振激发可以实现快速受控相位门(C-phase gate),结合单比特操作,可以快速实现C-NOT门.在两个相邻10 nm的NV色心之间,C-NOT门操作时间最快可达120 ns,比传统磁偶极方式快了2个量级.为了降低激发态自发辐射的影响,提出利用非共振腔抑制自发辐射.模拟结果显示C-phase门操控保真度可以达到98.88%.最后,将该方案扩展到一维NV色心自旋链.
基金V. ACKNOWLEDGMENTS This work was supported by the National Key Basic Research Program （No.2012CB922001 and No.2011CB921404）, the National Natural Science Foundation of China （No.21121003 and No.51172223）, the Strategic Priority Research Program of CAS （No.XDB01020300）, One Hundred Talent Program of CAS, the National Young Top Talent Program of Organization Department of China, the Fundamental Research Funds for the Central Universities （No.WK2060140014 and No.WK2060190025）, and USTCSCC, SCCAS, Tianjin, and Shanghai Supercomputer Centers.
文摘By using first principles calculations, four two-dimensional B-C-N ternary sheets with ordered and uniform element distribution are predicted based on the C, B, or N filled g-C3N4 sheet. These B-C-N ternary sheets are metallic except for B4-C3N4 monolayer, which is a semiconductor with an energy band gap of 1.18 eV. In particular, the BnC-C3N4 is a ferromagnetic metal with a net magnetic moment of 0.57 μB/cell, which can be used to develop metal-free spintronic device. The calculated formation energy indicates these B-C-N ternary sheets are highly thermal stable. It presents a new route to obtain uniform B-C-N ternary sheet for electronic and spintronic applications.
基金supported by the Ministry of Science and Technology of China (No.2016YFA0200602)the National Natural Science Foundation of China (No.21573211 and No.21633007)the Fundamental Research Funds for the Central Universities of China (No.WK2340000063)
文摘We report an ultrafast spectroscopy investigation that addresses the subtle location effect in a prototypical semiconductor-MOF hybrid system with TiO2 nanoparticles being incorporated inside or supported onto Cu3(BTC)2,denoted as TiO2@Cu3(BTC)2 and TiO2/Cu3(BTC)2,respectively.By tracking in real time the interface electron dynamics in the hybrid system,we find that the interface states formed between TiO2 and Cu3(BTC)2 can act as an effective relay for electron transfer,whose effciency rests on the relative location of the two components.It is such a subtle location effect that brings on difference in photocatalytic CO2 reduction using the two semiconductor-MOF hybrids.The mechanistic understanding of the involved interface electron-transfer behavior and effect opens a helpful perspective for rational design of MOF-based hybrid systems for photoelectrochemical applications.
基金supported by the Ministry of Science and Technology of China(No.2016YFA0400900 and No.2016YFA0200600)the National Natural Science Foundation of China(No.21573202 and No.21633006)the Fundamental Research Funds for the Central Universities(No.2340000074)
文摘Quantum dots comprise a type of quantum impurity system. The entanglement and co- herence of quantum states are significantly influenced by the strong electron-electron interactions among impurities and their dissipative coupling with the surrounding environment. Competition between many-body effects and transfer couplings plays an important role in determining the entanglement among localized impurity spins. In this work, we employ the hierarchical-equations-of-rnotion approach to explore the entanglement of a strongly correlated double quantum dots system. The relation between the total system entropy and those of subsystems is also investigated.
基金supported by the National Natural Science Foundation of China(No.21972129)the Ministry of Science and Technology of China(2016YFA0200603)Anhui Initiative in Quantum Information Technologies(AHY090000)。
文摘In view of the high activity of Pt single atoms in the low-temperature oxidation of CO,we investigate the adsorption behavior of Pt single atoms on reduced rutile TiO2(110)surface and their interaction with CO and O2 molecules using scanning tunneling microscopy and density function theory calculations.Pt single atoms were prepared on the TiO2(110)surface at 80 K,showing their preferred adsorption sites at the oxygen vacancies.We characterized the adsorption configurations of CO and O2 molecules separately to the TiO2-supported Pt single atom samples at 80 K.It is found that the Pt single atoms tend to capture one CO to form Pt-CO complexes,with the CO molecule bonding to the fivefold coordinated Ti(Ti5 c)atom at the next nearest neighbor site.After annealing the sample from 80 K to 100 K,CO molecules may diffuse,forming another type of complexes,Pt-(CO)2.For O2 adsorption,each Pt single atom may also capture one O2 molecule,forming Pt-O2 complexes with O2 molecule bonding to either the nearest or the next nearest neighboring Ti5c sites.Our study provides the single-molecule-level knowledge of the interaction of CO and O2 with Pt single atoms,which represent the important initial states of the reaction between CO and O2.
基金supported by the National Natural Science Foundation of China (No.21473178, No.21773222, No.21503203)the National Key R&D program of China (2017YFA0403403)+1 种基金the Key Program of Research and Development of Hefei Science Center of CAS(2017HSC-KPRD001)the Collaborative Innovation Center of Suzhou Nano Science and Technology
文摘Interfacial properties between perovskite layers and metal electrodes play a crucial role in the device performance and the long-term stability of perovskite solar cells.Here,we report a comprehensive study of the interfacial degradation and ion migration at the interface between CH3NH3PbI3 perovskite layer and Ag electrode.Using in situ photoemission spectroscopy measurements,we found that the Ag electrode could induce the degradation of perovskite layers,leading to the formation of PbI2 and AgI species and the reduction of Pb^2+ions to metallic Pb species at the interface.The unconventional enhancement of the intensities of I 3d spectra provides direct experimental evidences for the migration of iodide ions from CH3NH3PbI3 subsurface to Ag electrode.Moreover,the contact of Ag electrode and perovskite layers induces an interfacial dipole of 0.3 eV at CH3NH3PbI3/Ag interfaces,which may further facilitate iodide ion diffusion,resulting in the decomposition of perovskite layers and the corrosion of Ag electrode.
