“Negative” diamagnetism of three-dimensional arrays of semiconductor nano-rings

Authors


Corresponding author: e-mail vam@faculty.nctu.edu.tw, Phone: +886 3 5712121 ext: 54174, Fax: +886 37533722

Abstract

We theoretically study the orbital diamagnetic response of three-dimensional arrays of embedded InAs/GaAs wobbled nano-rings. To simulate the rings' magnetic characteristics, we use the effective one band Hamiltonian (energy and position-dependent electron effective mass and Landé factor) and smooth three-dimensional confinement potential that is mapping the actual strain and material content inside the rings. First, we obtain the magnetic susceptibility of an individual nano-ring. Once it is achieved, using the Claussius–Mossotti relation we estimate the effective susceptibility of three-dimensional arrays of the rings. We show that conventionally diamagnetic InAs/GaAs ring structures under certain conditions can demonstrate the positive peak of the effective magnetic susceptibility of the arrays, that we call “negative”-diamagnetic response. The “negative”-diamagnetic (positive susceptibility) peak remains Lorentz-like shaped and gradually disappears when the rings' concentration in the arrays decreases.

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