Nonlinear electronic transport in nanoscopic devices: Nonequilibrium Green's functions versus scattering approach
We study the nonlinear elastic quantum electronic transport properties of nanoscopic devices using the Nonequilibrium Green's function (NEGF) method. The Green's function method allows us to expand the $I-V$ characteristics of a given device to arbitrary powers of the applied voltages. By...
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Main Authors | , |
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Format | Journal Article |
Language | English |
Published |
12.07.2009
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Subjects | |
Online Access | Get full text |
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Summary: | We study the nonlinear elastic quantum electronic transport properties of
nanoscopic devices using the Nonequilibrium Green's function (NEGF) method. The
Green's function method allows us to expand the $I-V$ characteristics of a
given device to arbitrary powers of the applied voltages. By doing so, we are
able to relate the NEGF method to the scattering approach, showing their
similarities and differences and calculate the conductance coefficients to
arbitrary order. We demonstrate that the electronic current given by NEGF is
gauge invariant to all orders in powers of $V$, and discuss the requirements
for gauge invariance in the standard Density Functional Theory (DFT)
implementations in molecular electronics. We also analyze the symmetries of the
nonlinear conductance coefficients with respect to a magnetic field inversion
and the violation of the Onsager reciprocity relations with increasing
source-drain bias. |
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DOI: | 10.48550/arxiv.0907.2073 |