Zero field spin polarization in a two-dimensional paramagnetic resonant tunneling diode

Abstract

We study I-V characteristics of an all-II-VI semiconductor resonant tunneling diode with dilute magnetic impurities in the quantum well layer. Bound magnetic polaron states form in the vicinity of potential fluctuations at the well interface while tunneling electrons traverse these interface quantum dots. The resulting microscopic magnetic order lifts the degeneracy of the resonant tunneling states. Although there is no macroscopic magnetization, the resulting resonant tunneling current is highly spin polarized at zero magnetic field due to the zero field splitting. Detailed modeling demonstrates that the local spin polarization efficiency exceeds 90% without an external magnetic field.

Intrinsic oscillations of spin current polarization in a paramagnetic resonant tunneling diode

“…In such a spin filter, 16 the change of the spin polarization of the current requires the change of the external magnetic field. In the recently fabricated paramagnetic resonant tunneling diodes (RTDs) [17][18][19] , the electrical control of the spin polarization of the current has been achieved. The spinpolarized current is controlled by the bias voltage in the presence of the external magnetic field in paramagnetic RTDs 17,18,20,21 or even without the external magnetic field in ferromagnetic RTDs.…”

“…In the recently fabricated paramagnetic resonant tunneling diodes (RTDs) [17][18][19] , the electrical control of the spin polarization of the current has been achieved. The spinpolarized current is controlled by the bias voltage in the presence of the external magnetic field in paramagnetic RTDs 17,18,20,21 or even without the external magnetic field in ferromagnetic RTDs. [22][23][24][25][26][27] If the quantum well in the RTD is made from the DMS, the spin splitting of the quasi-bound state energy level gives rise to the a To be published in Phys.Rev.B.…”

“…The operation of the paramagnetic RTD based on ZnSe/ZnBeSe/ZnMnSe heterostructure as a spin filter has been experimentally demonstrated by Slobodskyy et al 17 and theoretically described by Havu et al 28 Recently, the spin polarization of the current in the paramagnetic RTD has been reported at zero magnetic field. 18 All these studies of the spin-polarized currents in the magnetic RTDs were devoted to the stationary (steady) currents. The oscillations of the spin-polarized currents in magnetic RTDs have not been studied until now, although the intrinsic oscillations of the current have been detected in the non-magnetic resonant tunneling structures.…”

Spin Polarization of Carriers in InGaAs Self-Assembled Quantum Rings Inserted in GaAs-AlGaAs Resonant Tunneling Devices

“…Resonant tunneling diodes (RTDs) have also been a research focus for many years [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] . Several works investigated their fundamental physical properties and possible potential applications in spintronics [8][9][10][11][12][13][14][15][16][17] .…”

“…Several works investigated their fundamental physical properties and possible potential applications in spintronics [8][9][10][11][12][13][14][15][16][17] . For example, it was shown that spin polarization of carriers in RTDs can be voltage and light dependent under magnetic field [8][9][10] .…”