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Published on: June 3, 2015
Pure spin current generation in monolayer graphene by quantum pumping.
Qingtian Zhang1, Zijing Lin, K S Chan
1Department of Physics, University of Science and Technology of China, Hefei, People's Republic of China.
Summary
Researchers demonstrate a novel method for generating pure spin currents in graphene using adiabatic quantum pumping. This technique, applicable across a wide Fermi energy range, shows promise for advancing graphene spintronic devices.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Mechanics
Background:
- Spintronics offers a promising alternative to conventional electronics by utilizing electron spin.
- Graphene, a 2D material, exhibits unique electronic properties suitable for spintronic applications.
- Generating pure spin currents efficiently is crucial for developing practical spintronic devices.
Purpose of the Study:
- To propose and investigate a method for generating pure spin currents in monolayer graphene.
- To explore the feasibility of this method across a broad range of Fermi energies.
- To analyze the influence of system parameters on the generated spin current.
Main Methods:
- Utilizing adiabatic quantum pumping with oscillating gate voltages.
- Employing a device architecture with gate electrodes and ferromagnetic strips for spin-splitting via proximity effect.
- Analyzing the dependence of spin current on Fermi energy and system parameters.
Main Results:
- A pure spin current is generated by applying periodic oscillating gate voltages.
- The pumped spin current exhibits a sensitive oscillatory dependence on Fermi energy.
- Significant spin currents are observed at Fermi energies corresponding to Fabry-Perot resonances.
- Predicted spin currents are on the order of 100 nA, measurable with current technology.
Conclusions:
- The proposed adiabatic quantum pumping method effectively generates pure spin currents in graphene.
- The technique is viable over a wide Fermi energy range and sensitive to Fabry-Perot resonances.
- This method provides a practical pathway for the development of graphene-based spintronic devices.
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