Shot noise of the spin inelastic tunneling through a quantum dot with single molecule-magnet

Abstract

We have studied the quantum fluctuations of inelastic spin-electron scattering in quantum dot with an embedded biaxial single molecule-magnet and particularly investigated the zero-frequency shot noise and Fano factor in different magnetic fields. It is found that the shot noise and Fano factor exhibit a stepwise behaviour as bias increases in the presence of interaction between the electron and molecule-magnet for a weak magnetic field. As magnetic field becomes strong, a dip is displayed in the shot-noise-bias curve due to the suppression of inelastic shot noise caused by the quantum tunneling of magnetisation. Because of the spontaneous inelastic tunneling at zero bias, a small shot noise occurs, which results in the case of Fano factor F ≫ 1. Moreover, our results show that the sweeping speed can also influence the shot noise and Fano factor obviously.

Multi-step shot noise spectrum induced by a local large spin

“…[5][6][7][8][9][10] Since Heersche et al [11] were able to trap an SMM in a typical field transistor geometry, great efforts have been devoted to measuring electronic transport through an SMM, which has a potential application for magnetic devices and quantum computation. [12] Although theoretical and experimental studies have revealed a lot of fascinating transport properties, such as negative differential conductance, [11,[13][14][15][16] current-induced switching, [17][18][19][20] Kondo effect, [21][22][23][24][25][26][27][28][29] Berry phase blockade, [2] and thermoelectric effect, [30,31] it is still very challenging in experiments to control such molecules. So it is natural to consider artificial counterparts of SMM, just like quantum dots as artificial counterparts of an atom.…”

Transport through artificial single-molecule magnets: Spin-pair state sequential tunneling and Kondo effects

“…[4][5][6] The realization of the magnetic singlemolecule transistor confirms the feasibility of the combination of the molecular electronics and spintronics. [3,6] In particular, theoretical and experimental studies on SMM quantum transport have exhibited a lot of fascinating transport properties such as negative differential conductance, [3,7] the Kondo effect, [4,5,[8][9][10] current-induced switching, [11][12][13] Berry phase blockade and oscillations, [1,14] graphene spintronics, [15,16] shot noise, [17][18][19][20] and so on. Although the single molecule magnets like Mn 12 have been trapped in a three-terminal transport setup and the electron transport through a single-molecule transistor can be probed, [3,6] the properties of the setup are dependent on the single molecule magnet and can hardly be tuned once it is fabricated.…”