Quantum phase transition and Coulomb blockade effect in triangular quantum dots with interdot capacitive and tunnel couplings |
| |
Authors: | Xiong Yong-Chen Wang Wei-Zhong Yang Jun-Tao Huang Hai-Ming |
| |
Institution: | a School of Science, Hubei University of Automotive Technology (HUAT), Shiyan 442002, China;b Department of Physics, Wuhan University, Wuhan 430072, China;c Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Wuhan 430072, China |
| |
Abstract: | The quantum phase transition and the electronic transport in a triangular quantum dot system are investigated using the numerical renormalization group method.We concentrate on the interplay between the interdot capacitive coupling V and the interdot tunnel coupling t.For small t,three dots form a local spin doublet.As t increases,due to the competition between V and t,there exist two first-order transitions with phase sequence spin-doublet-magnetic frustration phase-orbital spin singlet.When t is absent,the evolutions of the total charge on the dots and the linear conductance are of the typical Coulomb-blockade features with increasing gate voltage.While for sufficient t,the antiferromagnetic spin correlation between dots is enhanced,and the conductance is strongly suppressed for the bonding state is almost doubly occupied. |
| |
Keywords: | quantum phase transition Coulomb blockade effect triangular quantum dots strongly correlated system |
本文献已被 CNKI 等数据库收录! |
| 点击此处可从《中国物理 B》浏览原始摘要信息 |
| 点击此处可从《中国物理 B》下载免费的PDF全文 |
|