Metal-insulator transition(MIT)in perovskite iridium oxides Sr_(n+1)IrnO_(3n+1)represents one of the most attractive phenomena exemplifying the cooperation of Coulomb interaction and spin-orbit coupling(SOC).MIT takes...Metal-insulator transition(MIT)in perovskite iridium oxides Sr_(n+1)IrnO_(3n+1)represents one of the most attractive phenomena exemplifying the cooperation of Coulomb interaction and spin-orbit coupling(SOC).MIT takes place when Sr_(n+1)IrnO_(3n+1)(n=1,2)is doped with carriers.While electron-doped Sr_(n+1)IrnO_(3n+1)(n=1,2)systems have been extensively investigated,hole-doped samples are still limited.Here,we report the first growth of Fe-doped(hole-doped)Sr_(3)Ir_(2)O_(7)single crystals[Sr_3(Ir_(1-x)Fe_x)_(2)O_(7)]with the doping level 0.1≤x≤0.28.An MIT behavior is observed at the doping level of x~0.16 from resistivity measurements.Electronic structures of Fe-doped Sr_(3)Ir_(2)O_(7)have been revealed by angle-resolved photoemission spectroscopy(ARPES)measurements.The evident energy shift of the band structure indicates higher hole-doping level as compared with Rh-doped Sr_(3)Ir_(2)O_(7).Our results demonstrate that Fe doping serves as an effective approach for heavily hole doping in Sr_(3)Ir_(2)O_(7),thereby offering a powerful strategy to modulate MIT in this material system.展开更多
Ruddlesden-Popper iridate Sr_(3)Ir_(2)O_(7)is a spin-orbit coupled Mott insulator.Hole doped Sr_(3)Ir_(2)O_(7)provides an ideal platform to study the exotic quantum phenomena that occur near the metal-insulator transi...Ruddlesden-Popper iridate Sr_(3)Ir_(2)O_(7)is a spin-orbit coupled Mott insulator.Hole doped Sr_(3)Ir_(2)O_(7)provides an ideal platform to study the exotic quantum phenomena that occur near the metal-insulator transition(MIT)region.Rh substitution of Ir is an effective method to induce hole doping into Sr_(3)Ir_(2)O_(7).However,the highest doping level reported in Sr_(3)(Ir_(1-x)Rh_(x))_(2)O_(7)single crystals was only around 3%,which is far from the MIT region.In this paper,we report the successful growth of single crystals of Sr3(Ir_(1-x)Rh_(x))_(2)O_(7)with a doping level of~9%.The samples have been fully characterized,demonstrating the high quality of the single crystals.Transport measurements have been carried out,confirming the tendency of MIT in these samples.The electronic structure has also been examined by angle-resolved photoemission spectroscopy(ARPES)measurements.Our results establish a platform to investigate the heavily hole doped Sr_(3)Ir_(2)O_(7) compound,which also provide new insights into the MIT with hole doping in this material system.展开更多
The two-dimensional(2 D)kagome superconductor Cs V_(3)Sb_(5) has attracted much recent attention due to the coexistence of superconductivity,charge orders,topology and kagome physics,which manifest themselves as disti...The two-dimensional(2 D)kagome superconductor Cs V_(3)Sb_(5) has attracted much recent attention due to the coexistence of superconductivity,charge orders,topology and kagome physics,which manifest themselves as distinct electronic structures in both bulk and surface states of the material.An interesting next step is to manipulate the electronic states in this system.Here,we report angle-resolved photoemission spectroscopy(ARPES)evidence for a surface-induced orbitalselective band reconstruction in Cs V_(3)Sb_(5).A significant energy shift of the electron-like band aroundΓand a moderate energy shift of the hole-like band around M are observed as a function of time.This evolution is reproduced in a much shorter time scale by in-situ annealing of the Cs V_(3)Sb_(5) sample.Orbital-resolved density functional theory(DFT)calculations reveal that the momentum-dependent band reconstruction is associated with different orbitals for the bands aroundΓand M,and the time-dependent evolution points to the change of sample surface that is likely caused by the formation of Cs vacancies on the surface.Our results indicate the possibility of orbital-selective control of the band structure via surface modification,which may open a new avenue for manipulating exotic phenomena in this material system,including superconductivity.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.12074358)the National Key Research and Development Program of China(Grant No.2024YFA1408103)+2 种基金the International Partnership Program of the Chinese Academy of Sciences(Grant No.123GJHZ2022035MI)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302802)the Fundamental Research Funds for the Central Universities(Grant No.WK3510000015)。
文摘Metal-insulator transition(MIT)in perovskite iridium oxides Sr_(n+1)IrnO_(3n+1)represents one of the most attractive phenomena exemplifying the cooperation of Coulomb interaction and spin-orbit coupling(SOC).MIT takes place when Sr_(n+1)IrnO_(3n+1)(n=1,2)is doped with carriers.While electron-doped Sr_(n+1)IrnO_(3n+1)(n=1,2)systems have been extensively investigated,hole-doped samples are still limited.Here,we report the first growth of Fe-doped(hole-doped)Sr_(3)Ir_(2)O_(7)single crystals[Sr_3(Ir_(1-x)Fe_x)_(2)O_(7)]with the doping level 0.1≤x≤0.28.An MIT behavior is observed at the doping level of x~0.16 from resistivity measurements.Electronic structures of Fe-doped Sr_(3)Ir_(2)O_(7)have been revealed by angle-resolved photoemission spectroscopy(ARPES)measurements.The evident energy shift of the band structure indicates higher hole-doping level as compared with Rh-doped Sr_(3)Ir_(2)O_(7).Our results demonstrate that Fe doping serves as an effective approach for heavily hole doping in Sr_(3)Ir_(2)O_(7),thereby offering a powerful strategy to modulate MIT in this material system.
基金supported by the USTC start-up fundthe National Natural Science Foundation of China(Grant Nos.12074358 and 12004363)+2 种基金the Fundamental Research Funds for the Central Universities(Grant Nos.WK3510000008 and WK2030000035)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302802)supported by the U.S.Department of Energy,Office of Science,Office of Basic Energy Sciences under Contract No.DEAC02-76SF00515。
文摘Ruddlesden-Popper iridate Sr_(3)Ir_(2)O_(7)is a spin-orbit coupled Mott insulator.Hole doped Sr_(3)Ir_(2)O_(7)provides an ideal platform to study the exotic quantum phenomena that occur near the metal-insulator transition(MIT)region.Rh substitution of Ir is an effective method to induce hole doping into Sr_(3)Ir_(2)O_(7).However,the highest doping level reported in Sr_(3)(Ir_(1-x)Rh_(x))_(2)O_(7)single crystals was only around 3%,which is far from the MIT region.In this paper,we report the successful growth of single crystals of Sr3(Ir_(1-x)Rh_(x))_(2)O_(7)with a doping level of~9%.The samples have been fully characterized,demonstrating the high quality of the single crystals.Transport measurements have been carried out,confirming the tendency of MIT in these samples.The electronic structure has also been examined by angle-resolved photoemission spectroscopy(ARPES)measurements.Our results establish a platform to investigate the heavily hole doped Sr_(3)Ir_(2)O_(7) compound,which also provide new insights into the MIT with hole doping in this material system.
基金supported by the Fundamental Research Funds for the Central Universities(Grant Nos.WK3510000008 and WK3510000012)USTC start-up fund+3 种基金supported by the UC Santa Barbara NSF Quantum Foundry funded via the Q-AMASE-i program under award DMR-1906325the NSF Materials Research Science and Engineering Center at UC Santa Barbara(DMR-1720256)support from the California Nano Systems Institute through the Elings Fellowship programsupported by the National Science Foundation Graduate Research Fellowship Program under Grant No.DGE1650114。
文摘The two-dimensional(2 D)kagome superconductor Cs V_(3)Sb_(5) has attracted much recent attention due to the coexistence of superconductivity,charge orders,topology and kagome physics,which manifest themselves as distinct electronic structures in both bulk and surface states of the material.An interesting next step is to manipulate the electronic states in this system.Here,we report angle-resolved photoemission spectroscopy(ARPES)evidence for a surface-induced orbitalselective band reconstruction in Cs V_(3)Sb_(5).A significant energy shift of the electron-like band aroundΓand a moderate energy shift of the hole-like band around M are observed as a function of time.This evolution is reproduced in a much shorter time scale by in-situ annealing of the Cs V_(3)Sb_(5) sample.Orbital-resolved density functional theory(DFT)calculations reveal that the momentum-dependent band reconstruction is associated with different orbitals for the bands aroundΓand M,and the time-dependent evolution points to the change of sample surface that is likely caused by the formation of Cs vacancies on the surface.Our results indicate the possibility of orbital-selective control of the band structure via surface modification,which may open a new avenue for manipulating exotic phenomena in this material system,including superconductivity.
