We report an investigation on the single crystal growth,magnetic and transport properties of Eu In_(2)(As_(1-x)P_(x))_(2(0≤x≤1).The physical properties of axion insulator candidate Eu In;As;can be effectively tuned ...We report an investigation on the single crystal growth,magnetic and transport properties of Eu In_(2)(As_(1-x)P_(x))_(2(0≤x≤1).The physical properties of axion insulator candidate Eu In;As;can be effectively tuned by P-doping.With increasing x,the c-axis lattice parameter decreases linearly,the magnetic transition temperature gradually increases and ferromagnetic interactions are enhanced.This is similar to the previously reported high pressure effect on Eu In_(2)As_(2).For x=0.40,a spin glass state at T_(g)=10 K emerges together with the observations of a butter-fly shaped magnetic hysteresis and slow magnetic behavior.Besides,magnetic transition has great influence on the charge carriers in this system and negative colossal magnetoresistance is observed for all P-doped samples.Our findings suggest that Eu In_(2)(As_(1-x)P_(x))_(2) is a promising material playground for exploring novel topological states.展开更多
We review our most recent research on quantum transport,organizing the review according to the intensity of the magnetic field and focus mostly on topological semimetals and topological insulators.We first describe th...We review our most recent research on quantum transport,organizing the review according to the intensity of the magnetic field and focus mostly on topological semimetals and topological insulators.We first describe the phenomenon of quantum transport when a magnetic field is not present.We introduce the nonlinear Hall effect and its theoretical descriptions.Then,we discuss Coulomb instabilities in 3D higher-order topological insulators.Next,we pay close attention to the surface states and find a function to identify the axion insulator in the antiferromagnetic topological insulator MnBi2Te4.Under weak magnetic fields,we focus on the decaying Majorana oscillations which has the correlation with spin−orbit coupling.In the section on strong magnetic fields,we study the helical edge states and the one-sided hinge states of the Fermi-arc mechanism,which are relevant to the quantum Hall effect.Under extremely large magnetic fields,we derive a theoretical explanation of the negative magnetoresistance without a chiral anomaly.Then,we show how magnetic responses can be used to detect relativistic quasiparticles.Additionally,we introduce the 3D quantum Hall effect’s charge-density wave mechanism and compare it with the theory of 3D transitions between metal and insulator driven by magnetic fields.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.12074426,11227906and U2030106)the Fundamental Research Funds for the Central Universities,the Research Funds of Renmin University of China(Grant No.20XNLG19)。
文摘We report an investigation on the single crystal growth,magnetic and transport properties of Eu In_(2)(As_(1-x)P_(x))_(2(0≤x≤1).The physical properties of axion insulator candidate Eu In;As;can be effectively tuned by P-doping.With increasing x,the c-axis lattice parameter decreases linearly,the magnetic transition temperature gradually increases and ferromagnetic interactions are enhanced.This is similar to the previously reported high pressure effect on Eu In_(2)As_(2).For x=0.40,a spin glass state at T_(g)=10 K emerges together with the observations of a butter-fly shaped magnetic hysteresis and slow magnetic behavior.Besides,magnetic transition has great influence on the charge carriers in this system and negative colossal magnetoresistance is observed for all P-doped samples.Our findings suggest that Eu In_(2)(As_(1-x)P_(x))_(2) is a promising material playground for exploring novel topological states.
基金This work was supported by the National Key R&D Program of China(No.2022YFA1403700)the National Natural Science Foundation of China(No.11925402)+1 种基金Guangdong province(Nos.2020KCXTD001 and 2016ZT06D348)the Science,Technology and Innovation Commission of Shenzhen Municipality(Nos.ZDSYS20170303165926217,JAY20170412152620376,and KYTDPT20181011104202253).
文摘We review our most recent research on quantum transport,organizing the review according to the intensity of the magnetic field and focus mostly on topological semimetals and topological insulators.We first describe the phenomenon of quantum transport when a magnetic field is not present.We introduce the nonlinear Hall effect and its theoretical descriptions.Then,we discuss Coulomb instabilities in 3D higher-order topological insulators.Next,we pay close attention to the surface states and find a function to identify the axion insulator in the antiferromagnetic topological insulator MnBi2Te4.Under weak magnetic fields,we focus on the decaying Majorana oscillations which has the correlation with spin−orbit coupling.In the section on strong magnetic fields,we study the helical edge states and the one-sided hinge states of the Fermi-arc mechanism,which are relevant to the quantum Hall effect.Under extremely large magnetic fields,we derive a theoretical explanation of the negative magnetoresistance without a chiral anomaly.Then,we show how magnetic responses can be used to detect relativistic quasiparticles.Additionally,we introduce the 3D quantum Hall effect’s charge-density wave mechanism and compare it with the theory of 3D transitions between metal and insulator driven by magnetic fields.
