Collective properties of magnetobiexcitons in quantum wells and graphene superlattices
Collective properties of magnetobiexcitons in quantum wells and graphene superlattices
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DOI：
10.1103/physrevb.78.035135
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发表时间：
2008-01
影响因子：
3.7
通讯作者：
O. Berman;R. Kezerashvili;Y. Lozovik
中科院分区：
文献类型：
--
作者：
O. Berman;R. Kezerashvili;Y. Lozovik
研究了由半导体量子威尔斯（QWs）和石墨烯超晶格组成的具有交替电子和空穴层的超晶格中准二维空间间接磁双激子在强磁场下的玻色-爱因斯坦凝聚和超流性.在高磁场的极限下，由量子阱和石墨烯层（GL）组成的超晶格中具有偶极-偶极排斥的磁激子的稀释气体的两个不同的哈密顿量已经被简化为一个有效哈密顿量22 {}，一个具有磁激子的重整化有效质量的二维激子的稀释气体，其取决于磁场。这个哈密顿量不包括矢势。此外，对于$N$激子，我们已经减少了问题的$2N\ifmmode\times\else\texttimes\fi {}2$维空间的问题的$N\ifmmode\times\else\texttimes\fi{}2$维空间的电子和空穴的相对运动的坐标积分。本文研究了在强磁场中，电子层和空穴层交替排列的超晶格中相互作用的二维间接磁激子系统的基态不稳定性，并考虑了由一对具有相反偶极矩的间接激子组成的稳定的准二维间接磁双激子系统。在二维间接磁双激子系统中，以电四极子的形式相互作用，得到了量子阱和石墨烯实现的超流组分的密度和从Kosterlitz无相变到超流态的温度.
The Bose-Einstein condensation and superfluidity of quasi-two-dimensional spatially indirect magnetobiexcitons in a slab of superlattice with alternating electron and hole layers consisting from the semiconducting quantum wells (QWs) and graphene superlattice in high magnetic field are considered. The two different Hamiltonians of a dilute gas of magnetoexcitons with a dipole-dipole repulsion in superlattices, consisting of both QWs and graphene layers (GLs) in the limit of high magnetic field, have been reduced to one effective Hamiltonian\char22{}a dilute gas of two-dimensional excitons with the renormalized effective mass of the magnetoexciton, which depends on the magnetic field. This Hamiltonian does not include the vector potential. Moreover, for $N$ excitons we have reduced the problem of $2N\ifmmode\times\else\texttimes\fi{}2$-dimensional space onto the problem of $N\ifmmode\times\else\texttimes\fi{}2$-dimensional space by integrating over the coordinates of the relative motion of an electron and a hole. The instability of the ground state of the system of interacting two-dimensional indirect magnetoexcitons in a slab of superlattice with alternating electron and hole layers in high magnetic field is found. The stable system of indirect quasi-two-dimensional magnetobiexcitons, consisting of a pair of indirect excitons with opposite dipole moments, is considered. The density of the superfluid component ${n}_{s}(T)$ and the temperature of the Kosterlitz-Thouless phase transition to the superfluid state in the system of two-dimensional indirect magnetobiexcitons, interacting as electrical quadrupoles, are obtained for both the QW and graphene realizations.