We reported a study of tunnel magnetoresistance(TMR)effect in single manganite nanowire via the combination of magnetotransport and magnetic force microscopy imaging.TMR value up to 290%has been observed in single(La1...We reported a study of tunnel magnetoresistance(TMR)effect in single manganite nanowire via the combination of magnetotransport and magnetic force microscopy imaging.TMR value up to 290%has been observed in single(La1-yPry)1-x CaxMnO3 nanowires with varying width.We find that the TMR effect can be explained in the scenario of opening and blockade of conducting channels from inherent magnetic domain evolutions.Our findings provide a new route to fabricate TMR junctions and point towards future improvements in complex oxide-based TMR spintronics.展开更多
Complex oxides have rich functionalities and advantages for future technologies.In many systems,quenched disorder often holds the key to determine their physical properties,and these properties can be further tuned by...Complex oxides have rich functionalities and advantages for future technologies.In many systems,quenched disorder often holds the key to determine their physical properties,and these properties can be further tuned by chemical doping.However,understanding the role of quenched disorder is complicated because chemical doping simultaneously alters other physical variables such as local lattice distortions and electronic and magnetic environments.Here,we show that spatial confinement is an effective approach to tuning the level of quenched disorder in a complex-oxide system while leaving other physical variables largely undisturbed.Through the confinement of a manganite system down to quasi-one-dimensional nanowires,we observed that the nature of its metal-insulator phase transition exhibits a crossover from a discontinuous to a continuous characteristic,in close accordance with quenched disorder theories.We argue that the quenched disorder,finite size,and surface effects all contribute to our experimental observations.Noticeably,with reduced nanowire width,the magnetoresistance shows substantial enhancement at low temperatures.Our findings offer new insight into experimentally tuning the quenched disorder effect to achieve novel functionalities at reduced dimensions.展开更多
Light,acting as an external stimulus to induce various intriguing phenomena ranging from photovoltaics to photoinduced catalysis,exerts prominent effects in strongly correlated systems.It would be of particular intere...Light,acting as an external stimulus to induce various intriguing phenomena ranging from photovoltaics to photoinduced catalysis,exerts prominent effects in strongly correlated systems.It would be of particular interest to investigate photon-induced emerging phenomena in spatially confined strongly correlated systems,which are important for applications of these materials in future electronic devices.Colossal magnetoresistive manganites materials offer an ideal platform for such study due to their sensitivity to photo-excitation.Here,we fabricated 900 nm wide La_(0.325)Pr_(0.3)Ca_(0.375)Mn O_3strips,whose width is comparable to the size of the electronic phase separation(EPS)domains in this system.We observed the photoinduced critical fluctuations in the strips,where abrupt resistivity jumps occurred upon photoinduced phase transition depending sensitively on the light intensity.Based on the microscopic views of the EPS domains under photoexcitation,we conclude that such photo-induced resistivity fluctuations originate from the photoinduced phase fluctuations of individual EPS domains when their size becomes comparable to the strip width.展开更多
In correlated oxides,collaborative manipulation on light intensity,wavelength,pulse duration and polarization has yielded many exotic discoveries,such as phase transitions and novel quantum states.In view of potential...In correlated oxides,collaborative manipulation on light intensity,wavelength,pulse duration and polarization has yielded many exotic discoveries,such as phase transitions and novel quantum states.In view of potential optoelectronic applications,tailoring long-lived static properties by light-induced effects is highly desirable.So far,the polarization state of light has rarely been reported as a control parameter for this purpose.Here,we report polarization-dependent metal-to-insulator transition(MIT)in phaseseparated manganite thin films,introducing a new degree of freedom to control static MIT.Specifically,we observed giant photoinduced resistance jumps with striking features:(1)a single resistance jump occurs upon a linearly polarized light incident with a chosen polarization angle,and a second resistance jump occurs when the polarization angle changes;(2)the amplitude of the second resistance jump depends sensitively on the actual change of the polarization angles.Linear transmittance measurements reveal that the origin of the above phenomena is closely related to the coexistence of anisotropic micro-domains.Our results represent a first step to utilize light polarization as an active knob to manipulate static phase transitions,pointing towards new pathways for nonvolatile optoelectronic devices and sensors.展开更多
基金Project supported by the National Key Research and Development Program of China(Grant No.2016YFA0300702)Shanghai Municipal Natural Science Foundation,China(Grant Nos.19ZR1402800,18JC1411400,18ZR1403200,and 17ZR1442600)+1 种基金the Program of Shanghai Academic Research Leader,China(Grant Nos.18XD1400600 and 17XD1400400)the China Postdoctoral Science Foundation(Grant Nos.2016M601488 and 2017T100265)
文摘We reported a study of tunnel magnetoresistance(TMR)effect in single manganite nanowire via the combination of magnetotransport and magnetic force microscopy imaging.TMR value up to 290%has been observed in single(La1-yPry)1-x CaxMnO3 nanowires with varying width.We find that the TMR effect can be explained in the scenario of opening and blockade of conducting channels from inherent magnetic domain evolutions.Our findings provide a new route to fabricate TMR junctions and point towards future improvements in complex oxide-based TMR spintronics.
基金the National Key Research and Development Program of China(Grant No.2016YFA0300702)the Shanghai Municipal Natural Science Foundation(Grant Nos.19ZR1402800,18JC1411400,18ZR1403200,and 17ZR1442600)+1 种基金the Program of Shanghai Academic Research Leader(Grant Nos.18XD1400600,and 17XD1400400)the China Postdoctoral Science Foundation(Grant Nos.2016M601488,and 2017T100265)。
文摘Complex oxides have rich functionalities and advantages for future technologies.In many systems,quenched disorder often holds the key to determine their physical properties,and these properties can be further tuned by chemical doping.However,understanding the role of quenched disorder is complicated because chemical doping simultaneously alters other physical variables such as local lattice distortions and electronic and magnetic environments.Here,we show that spatial confinement is an effective approach to tuning the level of quenched disorder in a complex-oxide system while leaving other physical variables largely undisturbed.Through the confinement of a manganite system down to quasi-one-dimensional nanowires,we observed that the nature of its metal-insulator phase transition exhibits a crossover from a discontinuous to a continuous characteristic,in close accordance with quenched disorder theories.We argue that the quenched disorder,finite size,and surface effects all contribute to our experimental observations.Noticeably,with reduced nanowire width,the magnetoresistance shows substantial enhancement at low temperatures.Our findings offer new insight into experimentally tuning the quenched disorder effect to achieve novel functionalities at reduced dimensions.
基金supported by the National Key Research and Development Program of China(Grant No.2016YFA0300702)the National Basic Research Program of China(973 Program)(Grant No.2014CB921104)+1 种基金the Program of Shanghai Academic Research Leader(Grant No.17XD1400400)the National Natural Science Foundation of China(Grant No.11504053)
文摘Light,acting as an external stimulus to induce various intriguing phenomena ranging from photovoltaics to photoinduced catalysis,exerts prominent effects in strongly correlated systems.It would be of particular interest to investigate photon-induced emerging phenomena in spatially confined strongly correlated systems,which are important for applications of these materials in future electronic devices.Colossal magnetoresistive manganites materials offer an ideal platform for such study due to their sensitivity to photo-excitation.Here,we fabricated 900 nm wide La_(0.325)Pr_(0.3)Ca_(0.375)Mn O_3strips,whose width is comparable to the size of the electronic phase separation(EPS)domains in this system.We observed the photoinduced critical fluctuations in the strips,where abrupt resistivity jumps occurred upon photoinduced phase transition depending sensitively on the light intensity.Based on the microscopic views of the EPS domains under photoexcitation,we conclude that such photo-induced resistivity fluctuations originate from the photoinduced phase fluctuations of individual EPS domains when their size becomes comparable to the strip width.
基金supported by the National Key Research and Development Program of China(2022YFA1403300 and 2020YFA0309100)the National Natural Science Foundation of China(11991060,12074075,12074073,12074071,12074080,and 12274088)+3 种基金the Shanghai Municipal Science and Technology Major Project(2019SHZDZX01)the Shanghai Municipal Natural Science Foundation(20501130600,22ZR1408100,22ZR1407400,and 23ZR1407200)support from the National Key Research and Development Program of China(2021YFA1400503 and 2021YFA1400202)the National Natural Science Foundation of China(12125403,11874123,and 12221004).
文摘In correlated oxides,collaborative manipulation on light intensity,wavelength,pulse duration and polarization has yielded many exotic discoveries,such as phase transitions and novel quantum states.In view of potential optoelectronic applications,tailoring long-lived static properties by light-induced effects is highly desirable.So far,the polarization state of light has rarely been reported as a control parameter for this purpose.Here,we report polarization-dependent metal-to-insulator transition(MIT)in phaseseparated manganite thin films,introducing a new degree of freedom to control static MIT.Specifically,we observed giant photoinduced resistance jumps with striking features:(1)a single resistance jump occurs upon a linearly polarized light incident with a chosen polarization angle,and a second resistance jump occurs when the polarization angle changes;(2)the amplitude of the second resistance jump depends sensitively on the actual change of the polarization angles.Linear transmittance measurements reveal that the origin of the above phenomena is closely related to the coexistence of anisotropic micro-domains.Our results represent a first step to utilize light polarization as an active knob to manipulate static phase transitions,pointing towards new pathways for nonvolatile optoelectronic devices and sensors.
