Superpoissonian shot noise in organic magnetic tunnel junctions

Abstract

Organic molecules have recently revolutionized ways to create new spintronic devices. Despite intense studies, the statistics of tunneling electrons through organic barriers remains unclear. Here we investigate conductance and shot noise in magnetic tunnel junctions with PTCDA barriers a few nm thick. For junctions in the electron tunneling regime, with magnetoresistance ratios between 10 and 40\%, we observe superpoissonian shot noise. The Fano factor exceeds in 1.5-2 times the maximum values reported for magnetic tunnel junctions with inorganic barriers, indicating spin dependent bunching in tunneling. We explain our main findings in terms of a model which includes tunneling through a two level (or multilevel) system, originated from interfacial bonds of the PTCDA molecules. Our results suggest that interfaces play an important role in the control of shot noise when electrons tunnel through organic barriers.

References in corpus (13)

• Dipole formation at metal/PTCDA interfaces: Role of the Charge Neutrality Level
• Full counting statistics of super-Poissonian shot noise in multi-level quantum dots
• Noise enhancement due to quantum coherence in coupled quantum dots
• Shot noise in tunneling transport through molecules and quantum dots
• Evolution of the Kondo Effect in a Quantum Dot Probed by the Shot Noise
• Non-equilibrium Entanglement and Noise in Coupled Qubits
• Spin-polarized current and shot noise in the presence of spin flip in a quantum dot via nonequilibrium Green's functions
• Spin-torque shot noise in magnetic tunnel junctions
• Shot noise spectroscopy on a semiconductor quantum dot in the elastic and inelastic cotunneling regimes
• 1/f Tunnel Current Noise through Si-bound Alkyl Monolayers
• 1/f Tunnel Current Noise through Si-bound Alkyl Monolayers
• Controlling shot noise in double-barrier magnetic tunnel junctions
• Superpoissonian shot noise in organic magnetic tunnel junctions

Cited by in corpus (5)

• First-passage times in renewal and nonrenewal systems
• Nonrenewal statistics in transport through quantum dots
• Waiting time distribution revealing the internal spin dynamics in a double quantum dot
• Superpoissonian shot noise in organic magnetic tunnel junctions
• Shot noise in magnetic tunneling structures with two-level quantum dots