Off-plane Impurity Effects in Graphene Quantum Dots

Yıl 2016, Cilt: 37 Sayı: 1, 20 - 29, 19.01.2016

Defne Akay , Bekir Sıtkı Kandemir

https://doi.org/10.17776/csj.14715

Öz

Abstract. Within the continuum model of graphene, we study the properties of energy spectrum of graphene quantum dots in the presence of an off-plane donor/acceptor Coulomb impurities as a function of their positions. We propose a variational scheme in which the trial wave functions take into account the confinement of the carriers of graphene quantum dot together with the influence of magnetic field. The dependence of graphene quantum dot states on the location of impurity is investigated in the presence of magnetic field. We show that the off-plane donor/acceptor hydrogenic impurity removes the degeneracy of the relativistic Fock-Darwin states, and modifies the valley splitting due to the spatial confinement.

Keywords: Graphene quantum dots, Hydrogenic impurity

 

Özet. Grafenin sürekli modeli çerçevesinde, grafen kuantum noktalarının enerji spektrumu konumlarının bir fonksiyonu olarak düzlem dışı donör/akseptor Coulomb safsızlıklarının varlığında çalışılmıştır. Manyetik alanın etkisi altındaki grafen kuantum noktasının yük taşıyıcılarının sınırlanması göz önüne alınarak, varyasyonel yöntemde kullanılacak dalga fonksiyonu önerilmiştir. Grafen kuantum nokta durumlarının safsızlığın konumuna bağlılığı manyetik alanın varlığında incelenmiştir. Düzlem dışı donör/akseptör hidrojenik safsızlığın, göreli Fock-Darwin durumlarının dejenereliğini kaldırdığı ve uzaysal sınırlamadan dolayı vadi dejenereliğinin değiştiği görülmüştür.

Anahtar Kelimeler: Grafen kuantum noktaları, Hidrojenik safsızlık

Grafen Kuantum Noktalarında Düzlem Dışı Safsızlık Etkileri

Öz

Grafenin sürekli modeli çerçevesinde, grafen kuantum noktalarının enerji spektrumu konumlarının bir fonksiyonu olarak düzlem dışı donör/akseptor Coulomb safsızlıklarının varlığında çalışılmıştır. Manyetik alanın etkisi altındaki grafen kuantum noktasının yük taşıyıcılarının sınırlanması göz önüne alınarak, varyasyonel yöntemde kullanılacak dalga fonksiyonu önerilmiştir. Grafen kuantum nokta durumlarının safsızlığın konumuna bağlılığı manyetik alanın varlığında incelenmiştir. Düzlem dışı donör/akseptör hidrojenik safsızlığın, göreli Fock-Darwin durumlarının dejenereliğini kaldırdığı ve uzaysal sınırlamadan dolayı vadi dejenereliğinin değiştiği görülmüştür

Anahtar Kelimeler

Grafen kuantum noktaları, Hidrojenik safsızlık

Kaynakça

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