【摘 要】
：
We investigate the magnetism and optical absorption properties of charge neutral hexagonal graphene quantum dots (GQDs) terminated with zigzag edges by using a
【机 构】
：
Instrumental Analysis Center, Shanghai Jiao Tong University, Shanghai 200240“,”Key Laboratory of Art
论文部分内容阅读
We investigate the magnetism and optical absorption properties of charge neutral hexagonal graphene quantum dots (GQDs) terminated with zigzag edges by using a tight-binding Hubbard type model for the πr electrons.Within the Hartree-Fock approximation and taking into account the long-range Coulomb interaction,our calculation yields a ferromagnetic ground state with magnetic moments localized on the edges for GQDs,and also gives an antiferromagnetism state with the energy very close to the ferromagnetism ground state.We find that both the ferromagnetic and the antiferromagnetic states have stripe patteed charge density distributions as a result of the long-range Coulomb interaction.The optical conductivity for GQDs has an energy gap in the low frequency regime in contrast to the bulk neutral graphene sheet where a universal constant is approached.
其他文献
“涨价”意味着风险,也意味着机会,“涨”得好货如轮转,“涨”不好愁云惨淡宣布涨价的实质,就是要促使客户囤货,所谓同行竞争,在此时就是干方百计地抢占客户仓库库容和店面堆
体育教学是重要的教学内容，对学生综合素质的提高有着重要影响。当前，许多体育课的教学效果并不理想，学生在体育课上热情不高，课堂教学仅限于自由活动和简单的运动教学。伴随着游戏在体育教学中的应用，体育教学逐渐有了新的发展，这种方法可以提高学生的课堂参与度，激发学生的学习积极性。 一、游戏应用于体育教学中的意义 （一）丰富课堂内容，增加课堂乐趣 体育教学本就应该处于放松、快乐的氛围中，并且体育运动大
A semiclassical kinetic model is explored to investigate the wake effects in the transport of charged particles through single-walled (SWCNT) and double-walled
小学阶段的学生对游戏的喜好是本能的、强烈的,但是当游戏不断地重复后,学生难免会有枯燥无趣之感.如何让游戏在体育课堂中获得持久旺盛的生命力,并能够持续为教学服务呢?教
Zr-Ti binary alloys are prepared using a nonconsumable tungsten electrode under Ti-gettered inert atmosphere (argon).Microstructures are observed mainly as a ph
Heterogeneous nucleation in a conically shaped pit on the surface of a plane surface substrate is investigated.The growing process of a cluster on the substrate
Spintronics,which exploits electron spin in transport phenomena,has been a new branch in condensed matter physics in recent years.[1] Determining how to control
We investigate an excellent refrigeration capacity Rc of Gd55Al20Ni12Co10Mn3 bulk metallic glass (BMG).The Gd55Al20Ni12Co10Mn3 glassy rod is subjected to Cu mol
现如今,父母离异情况越来越普遍.家庭的完整程度对幼儿的心理、学业和品行等方面都会产生影响,因而教师在对幼儿开展集体活动时,也应当根据单亲家庭幼儿的生活背景、心理特征
一、小学科学教学现状 小学科学的教学难题便是科學知识如何与学习兴趣的结合。在传统的科学教学中，学生无法亲身体验科学的奥秘，这大大降低了他们对科学的热情，并限制了他们的想象力，使他们无法将科学与实际联系起来。小学科学教学的另一问题便是，教师在课堂上忽略了学生的生活经验和认知水平，仅凭自己的认知水平和生活经验进行教学，那么教学将失去其本来的意义，无法达到真正的要求和目的。 二、生活化教学的重要性