Room Temperature Current Suppression on Magnetic Tunnel Junction Based Molecular Spintronics Devices
- PDF / 826,375 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 71 Downloads / 161 Views
Room Temperature Current Suppression on Magnetic Tunnel Junction Based Molecular Spintronics Devices 1,2
Pawan Tyagi
1
Department of Chemical and Materials Engineering, University of Kentucky, Lexington, Kentucky-40506, USA 2 Current Address: School of Engineering and Applied Science, University of the District of Columbia, Washington DC-20008, USA. Email: [email protected] ABSTRACT Molecular conduction channels between two ferromagnetic electrodes can produce strong exchange coupling and dramatic effect on the spin transport, thus enabling the realization of novel logic and memory devices. To realize such device, we produced Multilayer Edge Molecular Spintronics Devices (MEMSDs) by bridging the organometallic molecular clusters (OMCs) across a ~2 nm thick insulator of a magnetic tunnel junction (MTJ), along its exposed side edges. These MEMSDs exhibited unprecedented increase in exchange coupling between ferromagnetic films and dramatic changes in the spin transport. This paper focuses on the dramatic current suppression phenomenon exhibited by MEMSDs at room temperature. In the event of current suppression, the effective MEMESDs’ current reduced by as much as six orders in magnitude as compared to the leakage current level of a MTJ test bed. Current suppression phenomenon was found to be associated with the equally dramatic changes in the MTJ test beds due to OMCs. Role of OMC in changing MTJ test bed properties was determined by the three different types of magnetic characterizations: SQUID Magnetometer, Ferromagnetic Resonance, and Magnetic Force Microscopy. Observation of current suppression by independent research groups and supporting studies on similar systems will be crucially important to unequivocally establish the utility of MEMSD approach. INTRODUCTION Molecular spintronics devices (MSDs) can revolutionize the computer’s logic and memory [1]. A MSD is a highly promising platform to enable the quantum computation [2, 3]. The MSD’s functioning depends upon manipulation of the spin degree of freedom of electron(s), requiring small energy for their manipulation. Such spin devices are expected to work with significantly lowered energy input, as compared to the charge-based devices. Novel MSDs are expected to evolve from a system of FM electrodes and molecule with a net spin. A number of intriguing phenomenon have been theoretically predicted for such systems [4-6]. For instance, Petrov et al. [5] predicted ~7 orders resistance change for the molecular bridges, which were initially antiferromagnetically coupled with the electrodes. Molecules are akin to quantum dots. Martinek et al. [7, 8] predicted the Kondo resonance for a system enabling the interaction between the spins of FM electrodes and the spin of quantum dots. Kondo resonance is the outcome of strong magnetic coupling between two magnetic entities. This observation was experimentally realized when C 60 molecule(s) bridged the nanogap between the two FM electrodes, on a Ni break junction [9].
Fabrication difficulties in producing reliable FM contac
Data Loading...
