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智科眼: 双语看懂新科研
普通物理 53
A(A) team(团队) led(领导) by(by) Osaka(大阪) University(大学) used(使用) angle()-()resolved(解决) photoelectron spectroscopy(光电子能谱) to(to) probe(探测) the unusual(异常) surface conductivity(表面电导) of(of) samarium() hexaboride(hexaboride) crystals(晶体).(.) They(他们) showed(表明) that(that) the material(材料) is(is) a(a) co-(共同)existing(存在) phase(阶段) of(of) "(")topological(拓扑) insulator(绝缘体)"(") in(in) which(which) electrical current(电流) can(可以) flow(流动) along(along) the surface(表面) but() not(不能) through(通过) the bulk() of(of) the sample(样品),(,) a(a) "(")Kondo(Kondo) insulator(绝缘体),"(,") which(which) undergoes(经历) a(a) metal(金属) to(to) insulator(绝缘体) transition(过渡) due to(由于) the strong() electron correlation(电子相关).(.) This(这项) work(工作),(,) which(which) demonstrates(证明) that(that) topological(拓扑) insulators(绝缘体) can(可以) simultaneously(同时) have(have) strong() electron(电子) correlations(相关性),(,) may(可以) allow(允许) for(for) the development(开发) of(of) quantum(量子) spin(自旋) devices(装置) that(that) use(使用) the magnetic spins(磁偶自旋) of(of) individual(单个) electrons(电子) to(to) outperform(优于) current(当前) computers(计算机).(.)
A(A) long(长期)-()standing(常设) debate(争论) has(has) existed(存在) regarding(关于) the metallic(金属) surface(表面) electronic structure(电子结构) of(of) samarium() hexaboride(hexaboride) (SmB6)((SmB6)) .(.) SmB6(SmB6) is(is) known(已知) to(to) be(be) an(一个) insulator(绝缘体) only() at(at) low temperatures(低温) due to(由于) strong() electron(电子) correlations(相关性),(,) called(称为) the "(")Kondo effect(近藤效应)."(.") Unlike(不同) most(大多数) materials(材料),(,) the resistance(电阻) in(in) Kondo(Kondo) insulators(绝缘子) actually(实际上) increases(增加) with(with) decreasing(降低) temperature(温度).(.) However(然而),(,) the origin(起源) of(of) the remnant(残余) conductivity(电导率) at(at) low temperatures(低温) has(has) not yet(尚末) been(been) revealed(揭示).(.) A(A) popular(流行) hypothesis(假设) is(is) that(that) SmB6(SmB6) is(is) also() a(a) topological(拓扑) insulator(绝缘体),(,) which(which) can(可以) have(have) metallic(金属) electronic states(电子状态) on(on) its() surface(表面).(.) However(然而),(,) the surface(表面) electronic structures(电子结构) of(of) SmB6(SmB6) obtained(获得) so far(迄今) have(have) been(been) complex(复杂) and() difficult(难以) to(to) interpret(解释) and() thus(因此) this(这个) question(问题) of(of) whether(是否) or(或者) not() SmB6(SmB6) is(is) indeed(确实) topological(拓扑) has(has) been(been) a(a) long(长期)-()standing(常设) debate(争论).(.) In(In) this(这项) work(工作),(,) the team(团队) observed(观察) the surface states(表面态) from(from) a(a) new(新的) crystal orientation(晶体取向) and() succeeded(成功) in(in) significantly(显著) simplifying(简化了) the surface states(表面态).(.)
The main(主要) insight(见解) was(was) measuring(测量) along(along) a(a) particular(特定) surface(表面) direction(方向),(,) which(which) had(had) previously(先前) been(been) difficult() to(to) do(do) .(.) To(To) obtain(获得) this(这个) surface(表面),(,) the researchers(研究人员) first(首先) had to(必须) prepare(准备) an(一个) atomically(原子级) flat(平坦),(,) extremely(非常) clean surface(清洁表面) of(of) the crystal(晶体) in(in) a(a) very(非常) precise(精确) manner(方式).(.) They(他们) accomplished(实现) this(这一) by(by) heating(加热) a(a) single crystal(单晶) of(of) samarium() hexaboride(hexaboride) to(to) very(非常) high temperatures(高温) in(in) an(一个) ultra-high vacuum(超高真空) chamber().(.) They(他们) then(然后) performed(进行) angle(角度)-()resolved(解决) photoelectron spectroscopy(光电子能谱),(,) which(which) monitors(监测) the electrons(电子) ejected(喷射) from(from) the crystal(晶体) when(when) exposed() to(to) intense() beams(光束) of(of) light().(.) Using(使用) a(a) ferromagnetic(铁磁) detector(探测器),(,) they(它们) were(were) able(能够) to(to) determine(确定) not only(不仅) the speeds(速度) of(of) the electrons(电子),(,) but also(而且) if(如果) they(他们) had(had) their(它们) spins(旋转) oriented(定向) up(up) or(或者) down(向下).(.) "We("We) were(were) able(能够) to(to) show(证明) that(that) samarium() hexaboride(hexaboride) is(is) a(a) topological(拓扑) insulator(绝缘体),(,) without(没有) any(任何) ambiguity(歧义),"(,") says() lead(领导) author(作者) Shin(胫骨)-()ichi(ichi) Kimura(Kimura).(.) "(")This(这个) opens() a(a) new(新的) research(研究) area(领域) in(in) which(which) strong(强烈) correlations(相关性) and() topological(拓扑) effects(效应) can(可能) exist(存在) in(in) the same(相同) material(材料)."(.")

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