Heat generation by electric current in mesoscopic devices

Abstract

We study the heat generation in a nano-device with an electric current passing through the device.For the first time, a general formula for the heat generation is derived by using the nonequilibrium Keldysh Green functions. This formula can be applied in both the linear and nonlinear transport regions, for time-dependent systems, and with multi-terminal devices. The formula is also valid when the nano-device contains various interactions. As an application of the formula, the heat generation of a lead-quantum dot-lead system is investigated. The dc and ac biases are studied in detail. We find several interesting behaviors that are unique to nanostructures, revealing significant difference from heat generation in macroscopic systems.

Raman scattering from biased molecular conduction junctions: The electronic background and its temperature

“…The issue of heating in biased molecular junctions has attracted considerable recent experimental and theoretical attention, motivated by the relevance of this phenomenon to current induced chemical change and to junction stability. 78,79 This issue was addressed theoretically by several workers, [80][81][82][83][84][85][86][87][88][89][90][91][92][93][94][95][96][97][98] however the experimental observation of such heating 12,13,[99][100][101][102][103][104][105] depends on finding a suitable probe. First attempt to estimate junction heating 100,101 have used the threshold for bond breaking under tension as such a probe.…”

Spin Effects on Heat Current Through a Quantum Dot Attached to Ferromagnetic Leads

“…This is mainly because the heat in mesoscopic structures is carried by phonons in a quantized way. Recently, Sun and Xie have calculated the heat generation from electric current by using the non-equilibrium Keldysh Green's function method and predicted some interesting phenomena unique in nanodevices [30]. For example, the heat generation can be very small despite a large current in the resonant tunneling region, which is favorable in device design [31].…”

“…This heat is a serious technological bottleneck of devices' miniaturization. Properties of local heating in nanostructures have been studied both experimentally [21][22][23][24][25][26][27][28] and theoretically [29][30][31][32][33][34][35][36][37][38][39][40] in recent years. Previous works have shown that although the heat generation in nano-scale or mesoscopic system is caused essentially by the same reasons as those in bulk macroscopic ones, some familiar laws of heat generation applicable in macroscopic systems, for example the Joule law, may not hold true in low-dimensional ones.…”

Transient heat generation in a quantum dot under a step-like pulse bias

“…As for the aspect of theory, on the one hand much efforts have been made to investigate the effects of inelastic e-p scattering on electronic transport through different nanostructures, [16][17][18][19][20][21][22][23][24] on the other hand many theoretical works have devoted to understanding the phenomena of heat, various models and methods were suggested as well. [25][26][27][28][29][30][31][32][33][34][35][36] By using the nonequilibrium Green's function (NEGF) method, a tractable formula of heat generation has been derived. 28 But these works mainly focused on the steady-state cases or, at most, the sinusoidal-like ac bias.…”

“…[25][26][27][28][29][30][31][32][33][34][35][36] By using the nonequilibrium Green's function (NEGF) method, a tractable formula of heat generation has been derived. 28 But these works mainly focused on the steady-state cases or, at most, the sinusoidal-like ac bias. In order to analyze the transient heat generation and its dynamics, the step-like and the square-shaped pulse biases are considered as the optimal driving forces.…”