Impurity magnetopolaron in a parabolic quantum dot: the squeezed-state variational approach


KANDEMİR B. S., Cetin A.

JOURNAL OF PHYSICS-CONDENSED MATTER, cilt.17, sa.4, ss.667-677, 2005 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 17 Sayı: 4
  • Basım Tarihi: 2005
  • Doi Numarası: 10.1088/0953-8984/17/4/009
  • Dergi Adı: JOURNAL OF PHYSICS-CONDENSED MATTER
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.667-677
  • Ankara Üniversitesi Adresli: Evet

Özet

We present a calculation of the ground-state binding energy of an impurity magnetopolaron confined in a three-dimensional (3D) parabolic quantum dot potential, in the framework of a variational approach based on two successive canonical transformations. First, we apply a displaced-oscillator type unitary transformation to diagonalize the relevant Frohlich Hamiltonian. Second, a single-mode squeezed-state transformation is introduced to deal with bilinear terms arising from the first transformation. Finally, the parameters of these transformations together with the parameters included in the electronic trial wavefunction are determined variationally to obtain the ground-state binding energy of an impurity magnetopolaron confined in a 3D parabolic quantum dot potential. Our approach has two advantages: first, the displaced-oscillator transformation allows one to obtain results valid for whole range of electronphonon coupling strength since it is,a special combination of Lee-Low-Pines and Huybrechts (LLP-H) canonical transformations, and second, the later transformation improves all-coupling results. It has been shown that the effects of quadratic terms arising from the all-coupling approach are very important and should-be taken into account in studying the size-dependent physical properties of nanostructured materials.