Recent studies demonstrate that novel 2D triphosphides semiconductors possess high carrier mobility and promising thermoelectric performance, while the carrier transport behaviors in 2D semimetal triphosphides have never been elucidated before. Herein, using the first-principles calculations and Boltzmann transport theory, we reveal that the electron-phonon coupling can be significant and thus greatly inhibits the electron and phonon transport in electron-doped BP3 and CP3. The intrinsic heat transport capacity of flexural acoustic phonon modes in the wrinkle structure is largely suppressed arising from the strong out-of-plane phonon scatterings, leading to the low phonon thermal conductivity of 1.36 and 5.33 W/(mK) for BP3 and CP3 at room temperature, and at high doping level, the enhanced scattering from electron diminishes the phonon thermal conductivity by 71% and 54% for BP3 and CP3, respectively. Instead, electron thermal conductivity shows nonmonotonic variations with the increase of doping concentration, stemming from the competition between electron-phonon scattering rates and electron group velocity. It is worth noting that the heavy-doping effect induced strong scattering from phonon largely suppresses the electron transport and reduces electron thermal conductivity to the magnitude of phonon thermal conductivity. This work sheds light on the electron and phonon transport properties in semimetal triphosphides monolayer and provides an efficient avenue for the modulation of carrier transport by doping-induced electron-phonon coupling effect.
Enhancement of spin-orbit coupling in Dirac semimetal Cd$_{3}$As$_{2}$ films by Sb-doping
研究了分子束外延生长的拓扑狄拉克半金属Cd $_{3}$ As $_{2}$掺杂Sb薄膜的磁输运性质。在我们的弱反局域化分析中,我们发现自旋轨道散射率的显着增强,表明Sb掺杂导致原始带反转能量的强烈增加。我们讨论了这种大的增强可能的起源通过比较Sb掺杂的镉$_{3}$作为$_{2}$与其他化合物半导体。Sb掺杂的Cd $_{3}$ As $_{2}$将是一个合适的体系,为进一步研究和功能化的拓扑狄拉克半金属。
Toward Tunable Magnetic Dirac Semimetals: Mn Doping of Cd$_3$As$_2$
National Laboratory of the Rockies(落基山国家实验室);King's College London(伦敦国王学院);National High Magnetic Field Laboratory(国家高磁场实验室);National Renewable Energy Laboratory(美国国家可再生能源实验室);University of Colorado, Boulder(科罗拉多大学博尔德分校)
Doping-induced superconductivity in the topological semimetal Mo5Si3
拓扑材料的化学掺杂为实现拓扑超导提供了一条可能的途径。然而,迄今为止已知的所有这些情况都是基于硫属化物。本文报道了Re掺杂在拓扑半金属Mo $_{5}$ Si $_{3}$中诱导超导电性的发现。Re部分取代Mo $_{5-x}$ Re $_{x}$ Si $_{3}$中的Mo导致晶胞的各向异性收缩,直至约$x$ = 2的溶解度极限。在很宽的掺杂范围内(0.5 $\leq$ $x$ $\leq$ 2),发现这些硅化物是具有完全各向同性带隙的弱耦合超导体。从1.67 K到5.78 K,$T_{\rm c}$随$x$单调增加,后者是同结构类型超导体中最高的。$T_{\rm c}$的这种变化趋势与价电子数的变化密切相关,主要归因于电子-声子耦合的增强。此外,能带结构计算表明,超导Mo $_{5-x}$ Re $_{x}$ Si $_{3}$具有非平凡的能带拓扑结构,其$Z_{2}$不变量为(1;000)或(1;111),这取决于Re的掺杂水平.我们的研究结果表明,过渡金属硅化物是一个肥沃的土壤探索候选拓扑超导体。
Strong-Coupling Superconductivity with $T_c$ $\sim$ 10.8 K Induced by P Doping in the Topological Semimetal Mo$_5$Si$_3$
通过对拓扑半金属Mo $_5$ Si $_3$中Si位进行P掺杂,发现Mo $_5$ Si $_{3-x}$ P $_x$(0.5 $\le$ $x$ $\le$ 2.0)具有强耦合超导电性. Mo $_5$ Si $_3$以空间群为$I4/mcm$(No.140)的W $_5$ Si $_3$型结构结晶,本身不是超导体.在P掺杂时,晶格参数$a$减小,而$c$单调增加。从电阻率、磁化强度和热容测量中揭示了Mo $_5$ Si $_{3-x}$ P $_x$(0.5 $\le$ $x$ $\le$ 2.0)的体超导性。Mo $_5$ Si $_{1.5}$ P $_{1.5}$中的$T_c$高达10.8 K,在W $_5$ Si $_3$型超导体中创下了新的纪录. Mo $_5$ Si $_{1.5}$ P $_{1.5}$的上、下临界场分别为14.56 T和105 mT。此外,发现Mo $_5$ Si $_{1.5}$ P $_{1.5}$是一个具有强电子-声子耦合的完全带隙超导体.第一性原理计算表明,电子-声子耦合的增强可能是由于电子掺杂引起的费米能级的移动。计算还揭示了Mo $_5$ Si $_3$的非平凡能带拓扑.在赝二元化合物中,Mo $_5$ Si $_{3-x}$ P $_x$的$T_c$和上临界场都很高.这两个都高于NbTi,使未来的应用前景。我们的研究结果表明,W…
Interfacial Oxidation Enables Charge-Transfer Contacts and Degenerate n-Doping in Monolayer MoS$_2$
Elettra - Sincrotrone Trieste S.C.p.A(的里雅斯特电子同步加速器股份有限公司);University of Udine(乌迪内大学);University of Trieste(的里雅斯特大学);Instituto de Ciencia de Materiales de Madrid (ICMM - CSIC)(马德里材料科学研究所(CSIC));CNR - Istituto Officina dei Materiali (IOM)(国家研究委员会材料工坊研究所);ArtemisProgram,U.K.Central Laser Facility, STFC Rutherford Appleton Laboratory(英国中央激光设施,STFC鲁瑟福阿普尔顿实验室);School of Physics and Astronomy, University of St Andrews(圣安德鲁斯大学物理与天文学学院);Department of Physics and Astronomy, Aarhus University(奥胡斯大学物理与天文学系)
Electron-doped magnetic Weyl semimetal LixCo3Sn2S2 by bulk-gating
RIKEN Center for Emergent Matter Science (CEMS)(RIKEN 新兴物质科学中心);Department of Mechanical Engineering and Sciences, Kyoto University(京都大学机械工学与科学系);Department of Physics, Tohoku University(东北大学物理学系);Research Center for Advanced Science and Technology, The University of Tokyo(东京大学先进科学技术研究中心);Quantum-phase Electronics Center and Department of Applied Physics, the University of Tokyo(东京大学量子相电子中心与应用物理系)
Record-high Mobility and Extreme Magnetoresistance on Kagome-lattice in Compensated Semimetal Ni3In2S2
kagome晶格晶体具有许多有趣的性质,包括阻挫磁性、电荷序、拓扑态、超导电性和相关现象。为了获得用于电子和自旋电子学应用的高性能卡戈梅晶格化合物,需要仔细调整能带结构。本文采用输运测量、角分辨光电子能谱和从头算方法研究了Kagome点阵晶体Ni 3 In 2S 2的电子结构。传输测量显示Ni 3 In 2S 2作为补偿半金属,具有创纪录的高载流子迁移率(空穴和电子的~8683 cm 2 V-1 S-1和7356 cm 2 V-1 S-1)和极端的磁阻(在2 K和13 T时为15518%)。这些特殊的性质很好地解释了它的能带结构与间接的间隙,小的电子/空穴口袋和大带宽的3d电子的Ni的kagome晶格。这项工作表明,晶体场和掺杂作为关键的调谐旋钮,以优化在kagome晶格晶体中的输运性质。我们的工作为kagome晶格半金属在电子学和自旋电子学方面的应用提供了材料基础和优化途径。
Electron doping in single crystalline BaBiO$_3$: BaBiO$_{3-x}$F$_{x}$
Indian Institute of Technology Palakkad(印度理工学院帕拉卡德分校);Raja Ramanna Centre for Advanced Technology(拉贾·拉曼纳先进技术中心);Homi Bhabha National Institute(霍米·巴巴国立研究所)