2021欧洲杯竞猜

浙大团队Science再发文!解密如何利用电场控制氧化物界面超导

发布时间:2021-05-24来源:欧洲杯竞猜app学术委员会作者:周炜0

铝酸镧(LaAlO3)和钽酸钾(KTaO3)是两种绝缘体,但当它们组合在一起时,界面就能导电甚至出现超导现象。这种刚刚“问世”的界面超导引发了科学家强烈的兴趣,来自欧洲杯竞猜app物理学系、中科院物理所等机构的学者发现,可以像调控半导体器件那样,用电压连续调控LaAlO3/KTaO3界面的导电性质:随着门电压的变化,它呈现了从超导到绝缘体的连续转变。同时,研究团队还在这一界面观测到了可被连续调控的量子金属态等许多新奇的物理现象。 

5月14日,相关论文Electric field control of superconductivity at the LaAlO3/KTaO3 (111) interface (电场控制LaAlO3/KTaO3 (111)界面超导)2021欧洲杯竞猜在《科学》杂志上线。论文的共同第一作者为浙大物理系博士生陈峥、刘源和北京航空航天大学博士后张慧,共同通讯作者是浙大物理学系谢燕武研究员,中科院物理所孙继荣研究员和周毅研究员。这一发现为人们探索低温量子现象呈现了一个崭新的视野,也为超导器件的研发提供了新的思路。

“后浪”的潜力 

laalo3/ktao3jiemianchaodaojinnian2yuecaiganggangzai《kexue》zazhizhengshi“liangxiang”。zaiyanghuawujiemianchaodaojiazuzhong,tashidi2weiruliedechengyuan。di1weichengyuanliangxiangyu2007nian,ruishirineiwadaxuedetrisconejiaoshoudengshouxianfaxianlelaalo3/srtio3jiemiancunzaichaodaoxianxiang,zheibiaozhizheyileixindechaodaotixidedansheng:yanghuawujiemianchaodao。

2021欧洲杯竞猜trisconecengyongyiduilegaojimulaixingrongzheiyilingyudeqimiao:butongdeyanghuawukeyichanshengqianbianwanhuadezuhe,meizhongzuhedouyoukenengyunhanzheweizhide、xinqidexingzhi。suihoudeyanjiufaxian,laalo3/srtio3dechaodaodianxingkeyitongguodianyalaikaiqihuoguanbi,jiuxiang2021ouzhoubeijingcaishuzhidebandaotijingtiguan。zheibujinrangrenchangxiang,huoxuyouyitian2021ouzhoubeijingcainengzhizaochuxiangbandaotiyiyangkeyijingquediaokongdechaodaoqijian。

 而一年多前“新生”于美国阿贡实验室的“后浪”LaAlO3/KTaO3的表现似乎更加抢眼。今年2月发表在《科学》杂志的论文指出,“LaAlO3/KTaO3的超导转变温度可达2.2 K,比“前浪”的0.3 K高出整整一个数量级。那么,它会有哪些新奇的性质?它的超导性能也能被调控吗?它对超导机制研究会有哪些价值?神秘的“后浪”吸引着谢燕武与他的合作伙伴们去一探究竟。

新的调控,新的机制 

diaokong,shishiyankexueyanjiuzuizhongyaodeshouduanheneirong。zaizheixiangyanjiuzhong,yanjiutuanduifaxianleyizhongquanxindediaokongjizhi,shixianlelaalo3/ktao3daodianxingnengdelianxukediao,qijiansuidianyabianhuachengxianlecongchaodaodaojueyuantidelianxuzhuanbian。

图:博士生陈峥和刘源在实验室制备样品 

2021欧洲杯竞猜xieyanwujieshao,daodiandianzizaidiwenxialiangliangpeidui,jiuhuixingchengchaodao,muqianyizhidechaodaotixiyijingfeichangduo,dannengbeidianchangdiaokongdefengmaolinjiao。“”2021ouzhoubeijingcaidediaokongfangfabenzhijiushidiaokongdianzi‘duixing’dekongjianfenbu,rangtamenzaigengkaojinhuogengyuanlijiemiandedifangyundong。”daliangdedianzizaiyanghuawujiemianfujinyundongshi,huishoudaojinggequexian(yechengwei“wuxu”)deyingxiang。“jiuxiangkaicheshiyudaozhangaiwu。”xieyanwushuo,zheizhong“wuxu”yuetiejinjiemianfenbuyuemiji,yueyuanlijiemianzeyuexishu。jiyuzheiyirenshi,yanjiutuanduitichulegaibiandianzikongjianfenbudesilu,“ruguoyougengduodedianzikaojinjiemian,neimezhengtilaikantamenyudaode‘zhangaiwu’jiubianduole,zheihuixianzhuyingxiangdianziyijipeiduihoudechaodaokupoduideyundongxingwei。”

图:每平方厘米界面通道里有80万亿个电子在运动,门电压通过改变它们的“队形”来影响界面导电性能。“山丘”形状示意了无序分布。 

2021欧洲杯竞猜zaizheixiangshiyanzhong,yanjiurenyuanceshilemendianyacong-200vdao150vqujianshijiemiandedaodianxingneng。“bulunzaichaodaozhuanbianwenduzhishanghaishizhixia,daodianxingdoukebeilianxudiaokong。”chenzhengshuo,“2021ouzhoubeijingcaihaizhijiecelianglezaizheiyimendianyaqujiandianzi‘duixing’kongjianfenbudebianhua,dangdaodiantongdaozai6namishi,laalo3/ktao3kanqilaishihenhaodechaodao,erdangtongdaodiaozhengdao2namishi,tajiuchenglejueyuanti。”

图:在-200V到150V区间施加不同门电压时LaAlO3/KTaO3界面的面电阻(Rsheet)随温度(T)的变化。 

2021欧洲杯竞猜“congbiaomiankan,2021ouzhoubeijingcaiyuchuantongdefangfayongdedoushimendianyadiaokong,danbeihoudediaokongjizhishiquanxinde。”sunjirongshuo,chuantongdefangfa,wulunshibandaotijingtiguanhaishilaalo3/srtio3,doushitongguogaibiandianzinongducongershixianduidaodianxingnengdediaokong,zheilixuyaoyougeqianti:dianzinongdudi。“xiangbizhixia,laalo3/ktao3jiemiandedianzinongduhengao,bunengmanzuchuantongdediaokongjizhi,yincixuyaotansuoquanxindediaokongjizhi。”sunjirongshuo,xindediaokongrengranyileisiyujingtiguandefangshigongzuo,danbenzhishangdapoleduiyudianzinongdudexianzhi。

 量子金属态 

2021欧洲杯竞猜boshishengchenzhengyuliuyuanquanchengcanyuleyangpindezhibeiheceshi。chenzhengshuo,yanjiuguochengzhongzuinanwangdeshidiyicicechulaalo3/ktao3chaodaoxingdeneiyitian,“biaoming2021ouzhoubeijingcaiyijingzhangwolezhibeizheiyixinjiemianchaodaotixidefangfa,keyikaishi2021ouzhoubeijingcaidediaokongyanjiule!”suizheshiyandetuijin,yuelaiyueduodeshujuyongxianchulai。dangtamenbatamenfangdaoyiqishi,jingqidifaxianzaidiwenxiashiyitiaoyouyitiaoshuipingxiantiao,yejiushishuo,wulunwenduzai0~1kdequjianneiruhebianhua,laalo3/ktao3jiemiandedianzujihushizhongshihengdingde。“liangzijinshushitongshijuyoubufenchaodaohejinshutexingdexinqiliangziwutai,zheishiyizhongdianxingdeliangzijinshutai。”zhouyishuo,“yizhideliangzijinshutaidouzhichuyumougeliangzilinjiedianshang。erzheigexitongkeyilianxudiaokong,liangzijinshuzuoweixiangtushangyigewuxiangdexingshicunzai,zheigexinfaxianling2021ouzhoubeijingcaiyichangjidong。”

图:器件实物照片。中间核心桥路部分宽20微米,长100微米。 

《科学》杂志的审稿人对这项研究给与了非常积极的回应,他们认为,这种完全可调的超导性是一项引人入胜的突破,该项研究充分深入,几乎覆盖了过去10多年人们在LaAlO3/SrTiO3体系中获得的认识。 

xieyanwushuo,duiyuxincailiaodeyanjiuzhuyaolaiziyuliangfangmiandongli:yifangmianxiangtongguoxincailiaodeyanjiulaifaxianxindewulixianxiang,huodegengduodekexuejianjie;lingyifangmianyeshituweikaifaxinqijiantigongyouyidexiansuo。“2021ouzhoubeijingcaizailaalo3/ktao3tixizhongdeyanjiukeweilijiechaodaojizhi,youqishilijiegaowenchaodaozhongdejizhitigongquanxindesucai,tongshiyeweijianglaikaifachaodaoqijiantigonglexindeshiye。”

这项研究的团队成员还包括浙大物理系博士生孙艳秋、张蒙,以及浙大材料学院田鹤教授和刘中然博士。 

研究得到了欧洲杯竞猜app量子交叉中心同仁在技术和设备等方面的全方位支持,同时还得到了欧洲杯竞猜app“双一流”建设专项经费、国家重点研发计划、国家自然科学基金、和浙江省重点研发计划等支持。

图:浙大物理系谢燕武课题组

 论文DOI:10.1126/science.abb3848

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