本文主要研究内容
作者白继元（2019）在《耦合多量子点干涉仪系统电输运理论研究》一文中研究指出：如何调控半导体量子点系统电输运一直是电子科技领域中具有广阔应用前景的研究课题。半导体量子点通常在单电子静电计、静态存储器元件、量子信息科学、量子计算等方面得以应用。与单量子点系统相比,耦合多量子点系统具有更多可调参数,可以更加容易地控制系统电荷输运、自旋极化输运和热电输运等。耦合多量子点可被用作集成量子芯片的基础电子元器件,而耦合多量子点系统电输运和热电转换的研究,则为设计与制备新型量子功能器件提供必要的理论支撑。本文利用Keldysh非平衡格林函数建立Dyson方程的方法,结合Langreth定理对几种不同构型的耦合多量子点干涉仪系统电荷输运、光子辅助电输运、自旋输运及热电输运进行理论研究。首先,在平行双量子点干涉仪结构基础上侧向悬挂一个量子点,设计成非对称三量子点干涉仪光子辅助电输运模型。通过调节量子点间耦合强度、含时外场的振幅和频率可以控制系统的平均电流峰值的大小和位置,实现介观器件的整流功能。对含时外场振幅的调控可实现系统平均电流峰与谷之间的转换。调节量子点-电极之间耦合强度的非对称性参数,能够使平均电流主峰与旁带峰更加易于区分,有助于确定系统能级的分立。其次,为使介观量子器件中的自旋极化电流得到更加有效地控制,设计了在Aharonov-Bhom干涉仪两臂中分别嵌入“T-型三量子点分子”模型,研究了该量子器件中光子辅助电荷及自旋输运特性。当有横向磁通穿过系统时,可观察到平均电流的Aharonov-Bhom效应。通过调节Rashba自旋-轨道耦合强度,可以在整个量子点能级区域内实现纯自旋向上(向下)的极化传输。在对称含时外场作用中,通过调节直流偏压、磁通和Rashba自旋-轨道耦合相位因子,自旋极化的大小和方向都可以有效地控制。在系统中施加时间调制的非对称外场能够实现多光子-电子泵功能。再次,设计并研究了“线型双量子点分子”Aharonov-Bohm干涉仪光子辅助电输运和“线型三量子点分子”Aharonov-Bohm干涉仪电输运。在“线型双量子点分子”Aharonov-Bohm干涉仪的研究中,调节量子点间耦合强度或磁通可以诱导电导共振峰发生劈裂。控制横向磁通的有无,可实现电导共振峰数值在0与1之间的相互转换,这为制造量子开关提供了一个新的物理解决方案。借助磁通和Rashba自旋-轨道相互作用,该系统可实现自旋过滤。对于“线型三量子点分子”Aharonov-Bohm干涉仪,当两个“线型三量子点分子”内点间耦合强度的数值差较小时,在电导谱中可以观察到Fano反共振峰。通过调节系统结构参数,可同时形成两个束缚态。随着磁通量相位因子在)0(-π范围内的增加,系统电导反共振点逐渐演变成反共振带。研究结果为“线型耦合多量子点分子链”嵌入Aharonov-Bohm干涉仪系统电输运的进一步研究提供了新的认知。最后,为提升介观量子器件的热电转换性能,在平行耦合双量子点基础上对称侧向悬挂单量子点。由于对称侧向悬挂量子点的耦合作用,在低温条件下电导谱和热导谱均产生了双Fano共振,这在很大程度上增强了系统热电转换性能。由于局域双极化效应与Fano效应的共同作用,该系统比平行耦合双量子点系统的热电优值提高一倍,基于此该系统可用于设计高效热电转换的量子器件。在相对高温条件下,通过调整量子点-电极耦合强度和量子点能级,可以实现系统热电优值的优化。总之,本文设计并研究了几种典型耦合多量子点干涉仪的电子输运、光子辅助电输运、自旋极化输运和热电输运。阐明了系统结构参数的调节可实现对电导、平均电流、自旋极化电流和热电参量的有效控制。这些典型耦合多量子点干涉仪系统对于实验来说结构并不复杂,对欧姆接触电极进行设计之后便可在实验中实现。本文的结论期望有助于自旋量子器件和热电转换量子器件的设计与研发。
Abstract
ru he diao kong ban dao ti liang zi dian ji tong dian shu yun yi zhi shi dian zi ke ji ling yu zhong ju you an kuo ying yong qian jing de yan jiu ke ti 。ban dao ti liang zi dian tong chang zai chan dian zi jing dian ji 、jing tai cun chu qi yuan jian 、liang zi xin xi ke xue 、liang zi ji suan deng fang mian de yi ying yong 。yu chan liang zi dian ji tong xiang bi ,ou ge duo liang zi dian ji tong ju you geng duo ke diao can shu ,ke yi geng jia rong yi de kong zhi ji tong dian he shu yun 、zi xuan ji hua shu yun he re dian shu yun deng 。ou ge duo liang zi dian ke bei yong zuo ji cheng liang zi xin pian de ji chu dian zi yuan qi jian ,er ou ge duo liang zi dian ji tong dian shu yun he re dian zhuai huan de yan jiu ,ze wei she ji yu zhi bei xin xing liang zi gong neng qi jian di gong bi yao de li lun zhi cheng 。ben wen li yong Keldyshfei ping heng ge lin han shu jian li Dysonfang cheng de fang fa ,jie ge Langrethding li dui ji chong bu tong gou xing de ou ge duo liang zi dian gan she yi ji tong dian he shu yun 、guang zi fu zhu dian shu yun 、zi xuan shu yun ji re dian shu yun jin hang li lun yan jiu 。shou xian ,zai ping hang shuang liang zi dian gan she yi jie gou ji chu shang ce xiang xuan gua yi ge liang zi dian ,she ji cheng fei dui chen san liang zi dian gan she yi guang zi fu zhu dian shu yun mo xing 。tong guo diao jie liang zi dian jian ou ge jiang du 、han shi wai chang de zhen fu he pin lv ke yi kong zhi ji tong de ping jun dian liu feng zhi de da xiao he wei zhi ,shi xian jie guan qi jian de zheng liu gong neng 。dui han shi wai chang zhen fu de diao kong ke shi xian ji tong ping jun dian liu feng yu gu zhi jian de zhuai huan 。diao jie liang zi dian -dian ji zhi jian ou ge jiang du de fei dui chen xing can shu ,neng gou shi ping jun dian liu zhu feng yu pang dai feng geng jia yi yu ou fen ,you zhu yu que ding ji tong neng ji de fen li 。ji ci ,wei shi jie guan liang zi qi jian zhong de zi xuan ji hua dian liu de dao geng jia you xiao de kong zhi ,she ji le zai Aharonov-Bhomgan she yi liang bei zhong fen bie qian ru “T-xing san liang zi dian fen zi ”mo xing ,yan jiu le gai liang zi qi jian zhong guang zi fu zhu dian he ji zi xuan shu yun te xing 。dang you heng xiang ci tong chuan guo ji tong shi ,ke guan cha dao ping jun dian liu de Aharonov-Bhomxiao ying 。tong guo diao jie Rashbazi xuan -gui dao ou ge jiang du ,ke yi zai zheng ge liang zi dian neng ji ou yu nei shi xian chun zi xuan xiang shang (xiang xia )de ji hua chuan shu 。zai dui chen han shi wai chang zuo yong zhong ,tong guo diao jie zhi liu pian ya 、ci tong he Rashbazi xuan -gui dao ou ge xiang wei yin zi ,zi xuan ji hua de da xiao he fang xiang dou ke yi you xiao de kong zhi 。zai ji tong zhong shi jia shi jian diao zhi de fei dui chen wai chang neng gou shi xian duo guang zi -dian zi beng gong neng 。zai ci ,she ji bing yan jiu le “xian xing shuang liang zi dian fen zi ”Aharonov-Bohmgan she yi guang zi fu zhu dian shu yun he “xian xing san liang zi dian fen zi ”Aharonov-Bohmgan she yi dian shu yun 。zai “xian xing shuang liang zi dian fen zi ”Aharonov-Bohmgan she yi de yan jiu zhong ,diao jie liang zi dian jian ou ge jiang du huo ci tong ke yi you dao dian dao gong zhen feng fa sheng pi lie 。kong zhi heng xiang ci tong de you mo ,ke shi xian dian dao gong zhen feng shu zhi zai 0yu 1zhi jian de xiang hu zhuai huan ,zhe wei zhi zao liang zi kai guan di gong le yi ge xin de wu li jie jue fang an 。jie zhu ci tong he Rashbazi xuan -gui dao xiang hu zuo yong ,gai ji tong ke shi xian zi xuan guo lv 。dui yu “xian xing san liang zi dian fen zi ”Aharonov-Bohmgan she yi ,dang liang ge “xian xing san liang zi dian fen zi ”nei dian jian ou ge jiang du de shu zhi cha jiao xiao shi ,zai dian dao pu zhong ke yi guan cha dao Fanofan gong zhen feng 。tong guo diao jie ji tong jie gou can shu ,ke tong shi xing cheng liang ge shu fu tai 。sui zhao ci tong liang xiang wei yin zi zai )0(-πfan wei nei de zeng jia ,ji tong dian dao fan gong zhen dian zhu jian yan bian cheng fan gong zhen dai 。yan jiu jie guo wei “xian xing ou ge duo liang zi dian fen zi lian ”qian ru Aharonov-Bohmgan she yi ji tong dian shu yun de jin yi bu yan jiu di gong le xin de ren zhi 。zui hou ,wei di sheng jie guan liang zi qi jian de re dian zhuai huan xing neng ,zai ping hang ou ge shuang liang zi dian ji chu shang dui chen ce xiang xuan gua chan liang zi dian 。you yu dui chen ce xiang xuan gua liang zi dian de ou ge zuo yong ,zai di wen tiao jian xia dian dao pu he re dao pu jun chan sheng le shuang Fanogong zhen ,zhe zai hen da cheng du shang zeng jiang le ji tong re dian zhuai huan xing neng 。you yu ju yu shuang ji hua xiao ying yu Fanoxiao ying de gong tong zuo yong ,gai ji tong bi ping hang ou ge shuang liang zi dian ji tong de re dian you zhi di gao yi bei ,ji yu ci gai ji tong ke yong yu she ji gao xiao re dian zhuai huan de liang zi qi jian 。zai xiang dui gao wen tiao jian xia ,tong guo diao zheng liang zi dian -dian ji ou ge jiang du he liang zi dian neng ji ,ke yi shi xian ji tong re dian you zhi de you hua 。zong zhi ,ben wen she ji bing yan jiu le ji chong dian xing ou ge duo liang zi dian gan she yi de dian zi shu yun 、guang zi fu zhu dian shu yun 、zi xuan ji hua shu yun he re dian shu yun 。chan ming le ji tong jie gou can shu de diao jie ke shi xian dui dian dao 、ping jun dian liu 、zi xuan ji hua dian liu he re dian can liang de you xiao kong zhi 。zhe xie dian xing ou ge duo liang zi dian gan she yi ji tong dui yu shi yan lai shui jie gou bing bu fu za ,dui ou mu jie chu dian ji jin hang she ji zhi hou bian ke zai shi yan zhong shi xian 。ben wen de jie lun ji wang you zhu yu zi xuan liang zi qi jian he re dian zhuai huan liang zi qi jian de she ji yu yan fa 。
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论文作者分别是来自哈尔滨工程大学的白继元，发表于刊物哈尔滨工程大学2019-07-01论文，是一篇关于非平衡格林函数论文,量子点论文,光子辅助隧穿论文,效应论文,热电输运论文,哈尔滨工程大学2019-07-01论文的文章。本文可供学术参考使用，各位学者可以免费参考阅读下载，文章观点不代表本站观点，资料来自哈尔滨工程大学2019-07-01论文网站，若本站收录的文献无意侵犯了您的著作版权，请联系我们删除。
标签：非平衡格林函数论文; 量子点论文; 光子辅助隧穿论文; 效应论文; 热电输运论文; 哈尔滨工程大学2019-07-01论文;