We have studied the characteristics of current-induced nonequilibrium spin polarization in semiconductor-nanowire/swave superconductor junctions with strong spin–orbit coupling. It was found that within some paramete...We have studied the characteristics of current-induced nonequilibrium spin polarization in semiconductor-nanowire/swave superconductor junctions with strong spin–orbit coupling. It was found that within some parameter regions the magnitude of the current-induced nonequilibrium spin polarization density in such structures will increase（or decrease） with the decrease（or increase） of the charge current density, in contrast to that found in normal spin–orbit coupled semiconductor structures. It was also found that the unusual characteristics of the current-induced nonequilibrium spin polarization in such structures can be well explained by the effect of the Andreev reflection.展开更多
(1)The caption of Fig.11 erroneously states“(c)Reproduced with permission from Debessai et al.,Phys.Rev.Lett.102,197002(2009).Copyright 2009 the American Physical Society.”Instead it should state“(c)Reproduced with...(1)The caption of Fig.11 erroneously states“(c)Reproduced with permission from Debessai et al.,Phys.Rev.Lett.102,197002(2009).Copyright 2009 the American Physical Society.”Instead it should state“(c)Reproduced with permission from Debessai et al.,Phys.Rev.B 78,064519(2008).Copyright 2008 the American Physical Society.”展开更多
A material termed“carbonaceous sulfur hydride”has recently been reported to be a high-pressure room temperature superconductor[Snider et al.,Nature 586,373(2020)].We have previously pointed out that certain anomalie...A material termed“carbonaceous sulfur hydride”has recently been reported to be a high-pressure room temperature superconductor[Snider et al.,Nature 586,373(2020)].We have previously pointed out that certain anomalies observed in the published data for the ac magnetic susceptibility of this material would be cleared up once the measured raw data were made available[J.E.Hirsch,arXiv:2110.12854v1(2021)and J.E.Hirsch,Physica C 590,1353964(2021)(temporarily removed)].The measured raw data,as well as numerical values of the data presented in figures in the aforementioned paper by Snider et al.,have recently been posted on the arXiv[R.P.Dias and A.Salamat,arXiv:2111.15017v1(2021)and R.P.Dias and A.Salamat,arXiv:2111.15017v2(2021)].Here,we report the results of our analysis of these raw data and published data and our conclusion that the raw data are incompatible with the published data.Implications of these results for the claim that the material is a room temperature superconductor are discussed.展开更多
Metal-oxide-semiconductor field-effect transistor(MOSFET)and complementary metal-oxide-semiconductor(CMOS)circuits are the foundation of integrated circuits development and the cornerstone of information infrastructur...Metal-oxide-semiconductor field-effect transistor(MOSFET)and complementary metal-oxide-semiconductor(CMOS)circuits are the foundation of integrated circuits development and the cornerstone of information infrastructure and artificial intelligence(AI)progress[1-3].However,as the physical scale of devices continues to shrink,Moore’s Law has faced limitations,and short channel effects(SCEs)have become increasingly severe[4,5].展开更多
Nanoelectromechanical(NEM)switches have the advantages of zero leakage current,abrupt switching characteristics,and harsh environmental capabilities.This makes them a promising component for digital computing circuits...Nanoelectromechanical(NEM)switches have the advantages of zero leakage current,abrupt switching characteristics,and harsh environmental capabilities.This makes them a promising component for digital computing circuits when high energy efficiency under extreme environmental conditions is important.However,to make NEM-based logic circuits commercially viable,NEM switches must be manufacturable in existing semiconductor foundry platforms to guarantee reliable switch fabrication and very large-scale integration densities,which remains a big challenge.Here,we demonstrate the use of a commercial silicon-on-insulator(SOI)foundry platform(iSiPP50G by IMEC,Belgium)to implement monolithically integrated silicon(Si)NEM switches.Using this SOI foundry platform featuring sub-200 nm lithography technology,we implemented two different types of NEM switches:(1)a volatile 3-terminal(3-T)NEM switch with a low actuation voltage of 5.6 V and(2)a bi-stable 7-terminal(7-T)NEM switch,featuring either volatile or non-volatile switching behavior,depending on the switch contact design.The experimental results presented here show how an established CMOS-compatible SOI foundry process can be utilized to realize highly integrated Si NEM switches,removing a significant barrier towards scalable manufacturing of high performance and high-density NEMbased programmable logic circuits and non-volatile memories.展开更多
In high temperature oxide superconductors, such as Sr-La-Cu-O,Ba-Y-Cu-O, there is a phase transition from semiconductor to metal as the composition changes under the same condition of heat treatment. Recently the theo...In high temperature oxide superconductors, such as Sr-La-Cu-O,Ba-Y-Cu-O, there is a phase transition from semiconductor to metal as the composition changes under the same condition of heat treatment. Recently the theoretical explanations are proposed, hut the research is still at an initial stage. Thus study in different ways on the cause of the phase transition and its relationship with high temperature superconductivity is one of the important current subjects.展开更多
The great deal of novel rare earth based semiconducting lanthanum barium copper oxide La3Ba3Cu6OI4 （LBC-336） were synthesized by low temperature molten salt synthesis （MSS） due to ＂dissolution precipitation mecha...The great deal of novel rare earth based semiconducting lanthanum barium copper oxide La3Ba3Cu6OI4 （LBC-336） were synthesized by low temperature molten salt synthesis （MSS） due to ＂dissolution precipitation mechanism＂. Here, we reported one pot synthesis of product by direct precipitation from a molten KOH-NaOH mixnare at 450 ℃ and single phase La3Ba3Cu6014 with tetragonal crystal system. The particle size of 140-200 nm were observed in both PXRD pattern and HRSEM micrographs and it showed a cubic morphology. The semiconducting nature was extracted from various parameters like optical band gap （1.8 eV）, AC conductivity （0.70 eV）, DC conductivity （0.70 eV）, and also Hall effect parameters like the charge carrier concentration values n=6,0x 1026 m-3 and it proved as a p-type semiconductor. The electrical phase trasition temperature from ferroelectric to antiferroelec- tric system （Tin=420 K） and anti-ferroelectric - paraelectric system （depolarization temperature Ta=673 K） which attributed to the space charge polarization contributed to the conduction mechanism. The magnetic phase transitions were from ferromagnetic to ferrimagnetic system （Curie temperature （Tc=70 K）） and it led to soft magnetic material and also held good for superconductor appli- cation upto 70 K.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.11474106)
文摘We have studied the characteristics of current-induced nonequilibrium spin polarization in semiconductor-nanowire/swave superconductor junctions with strong spin–orbit coupling. It was found that within some parameter regions the magnitude of the current-induced nonequilibrium spin polarization density in such structures will increase（or decrease） with the decrease（or increase） of the charge current density, in contrast to that found in normal spin–orbit coupled semiconductor structures. It was also found that the unusual characteristics of the current-induced nonequilibrium spin polarization in such structures can be well explained by the effect of the Andreev reflection.
文摘(1)The caption of Fig.11 erroneously states“(c)Reproduced with permission from Debessai et al.,Phys.Rev.Lett.102,197002(2009).Copyright 2009 the American Physical Society.”Instead it should state“(c)Reproduced with permission from Debessai et al.,Phys.Rev.B 78,064519(2008).Copyright 2008 the American Physical Society.”
文摘A material termed“carbonaceous sulfur hydride”has recently been reported to be a high-pressure room temperature superconductor[Snider et al.,Nature 586,373(2020)].We have previously pointed out that certain anomalies observed in the published data for the ac magnetic susceptibility of this material would be cleared up once the measured raw data were made available[J.E.Hirsch,arXiv:2110.12854v1(2021)and J.E.Hirsch,Physica C 590,1353964(2021)(temporarily removed)].The measured raw data,as well as numerical values of the data presented in figures in the aforementioned paper by Snider et al.,have recently been posted on the arXiv[R.P.Dias and A.Salamat,arXiv:2111.15017v1(2021)and R.P.Dias and A.Salamat,arXiv:2111.15017v2(2021)].Here,we report the results of our analysis of these raw data and published data and our conclusion that the raw data are incompatible with the published data.Implications of these results for the claim that the material is a room temperature superconductor are discussed.
文摘Metal-oxide-semiconductor field-effect transistor(MOSFET)and complementary metal-oxide-semiconductor(CMOS)circuits are the foundation of integrated circuits development and the cornerstone of information infrastructure and artificial intelligence(AI)progress[1-3].However,as the physical scale of devices continues to shrink,Moore’s Law has faced limitations,and short channel effects(SCEs)have become increasingly severe[4,5].
基金the European Union’s Horizon 2020 research and innovation program under grant No.780283(MORPHIC),101070332(PHORMIC),871740(ZeroAMP)the i-EDGE project,funded by the European Union(No.101092018)+1 种基金the Swiss State Secretariat for Education,Research and Innovation(SERI No.10061130)UK Research and Innovation(UKRI No.10063023).
文摘Nanoelectromechanical(NEM)switches have the advantages of zero leakage current,abrupt switching characteristics,and harsh environmental capabilities.This makes them a promising component for digital computing circuits when high energy efficiency under extreme environmental conditions is important.However,to make NEM-based logic circuits commercially viable,NEM switches must be manufacturable in existing semiconductor foundry platforms to guarantee reliable switch fabrication and very large-scale integration densities,which remains a big challenge.Here,we demonstrate the use of a commercial silicon-on-insulator(SOI)foundry platform(iSiPP50G by IMEC,Belgium)to implement monolithically integrated silicon(Si)NEM switches.Using this SOI foundry platform featuring sub-200 nm lithography technology,we implemented two different types of NEM switches:(1)a volatile 3-terminal(3-T)NEM switch with a low actuation voltage of 5.6 V and(2)a bi-stable 7-terminal(7-T)NEM switch,featuring either volatile or non-volatile switching behavior,depending on the switch contact design.The experimental results presented here show how an established CMOS-compatible SOI foundry process can be utilized to realize highly integrated Si NEM switches,removing a significant barrier towards scalable manufacturing of high performance and high-density NEMbased programmable logic circuits and non-volatile memories.
文摘In high temperature oxide superconductors, such as Sr-La-Cu-O,Ba-Y-Cu-O, there is a phase transition from semiconductor to metal as the composition changes under the same condition of heat treatment. Recently the theoretical explanations are proposed, hut the research is still at an initial stage. Thus study in different ways on the cause of the phase transition and its relationship with high temperature superconductivity is one of the important current subjects.
基金VIT University for providing major financial support
文摘The great deal of novel rare earth based semiconducting lanthanum barium copper oxide La3Ba3Cu6OI4 （LBC-336） were synthesized by low temperature molten salt synthesis （MSS） due to ＂dissolution precipitation mechanism＂. Here, we reported one pot synthesis of product by direct precipitation from a molten KOH-NaOH mixnare at 450 ℃ and single phase La3Ba3Cu6014 with tetragonal crystal system. The particle size of 140-200 nm were observed in both PXRD pattern and HRSEM micrographs and it showed a cubic morphology. The semiconducting nature was extracted from various parameters like optical band gap （1.8 eV）, AC conductivity （0.70 eV）, DC conductivity （0.70 eV）, and also Hall effect parameters like the charge carrier concentration values n=6,0x 1026 m-3 and it proved as a p-type semiconductor. The electrical phase trasition temperature from ferroelectric to antiferroelec- tric system （Tin=420 K） and anti-ferroelectric - paraelectric system （depolarization temperature Ta=673 K） which attributed to the space charge polarization contributed to the conduction mechanism. The magnetic phase transitions were from ferromagnetic to ferrimagnetic system （Curie temperature （Tc=70 K）） and it led to soft magnetic material and also held good for superconductor appli- cation upto 70 K.
