Inelastic Heat Conduction in Molecular Quantum Systems

After several weeks I have challenged and learned many things about physics. This subject may be hated by many people which is understandable but there is still many things to be discovered which makes me more impatient.                                                                               The quantum heat transporters for lattice vibration, phonons, electrons and electromagnetic fluctuations which distance is very short compared with our macroscopic world. The purpose of my research is to study electron-phonon coupling effects on electronic heat transfer at molecular levels. How electron interaction work and how does it lead to phonon-mediated changes the characteristics in transport. A brief definition of thermal conductivity is defined as a ratio of energy flux and temperature gradient. Once the phonons move freely, arbitrary energy flux will be there without temperature gradient so the finite phonon velocity will not make the thermal conductivity final. So basically, the conductivity increases with temperature because the phonons carry more energy.              In this work, we used non-perturbative functions and well known formulas  in order to present atomic preciseness combining microscopic Maxwell equations and atomic Green’s function to grasp the physical picture of the transition from photon-mediated thermal radiation to phonon-mediated heat conduction at connection. That is why with the help of these formulas we have formed a scheme described as the“Ladder Model” to help understand and generate definite results.

After couple of trials the scheme above used to conclude that there is dynamics which the electron-phonon interaction on the molecule connected by  two different thermal reservoirs. This effect is thermal rectification proving that the thermal properties of molecular systems are conducted as finite temperatures and this action of molecular transport is in the presence of molecular vibrations- phonons. Appropriate graph  model of thermal conductance and temperatures easily presents that at low temperatures there is a stronger electron-phonon coupling interaction where at higher temperatures there is more dynamic phonons in the inelastic conduction process.                                                                    As for our future studies we will be contemplating high intensity heat fluxes and their disruptions, expanding used energy-domain transport preciseness onto  time-dependent development to analyze the relaxation processes in the presence of strong electron-phonon interaction effects. An important factor for future studies will be a detailed analysis of phonon sidebands onto heat conduction along with realistic biological systems due to their molecular complexities.



Step by step to Inelastic Heat Conduction via Molecular Quantum Systems

Summer just started and most of us are now on vacation enjoying the heat from the sun rays. Well for me this summer is working with the HEAT but the one in thermodynamics- one of the greatest topics in physics. Our goal is to examine the study of electron-phonon coupling effects of heat conditions in very “tiny” other words molecular complexes. These couple of weeks are starting to fall into place once meeting my Professor Walczak working on my research titles” Inelastic Heat Conduction via Molecular Quantum Systems”- where misleading concepts are finally clearing up. It all begins when we have installed MATLAB on our laptops- a software to help analyze our data .With basic commands the one we use daily on our computers to edit files and input data. In addition, all the results and complicated equations we will use the help of MATLAB. This program makes my results clear when plotting different visual graphs. I’m still in progress of working with sample problems just to refine my skills and experimenting with all the possibilities this program can do.                                                            This research is the typical research done in chemistry or biology labs because it’s not experimental but more theoretical based. The results I’m currently working with is mostly synthesis of current data something we are figuring out and demonstrating  in the long run for the need of more data.In this case we use non-perturbative computational format to base of Landauer formula:

Another great equation is working on Green’s functions technique that is used for calculating multi-channel transmission probability functionwhere the individual conduction channel is used by the Boltzmans’ equation We want to focus mainly on expanding aspect ions like the strength of electron-phonon coupling and the heat fluxes that occur due to the temperature change and bias voltage which can get tricky at times. So far, I’ve been enjoying MATLAB it is amazing to have all the data in one place. Keeping track and planning out as well as debugging the code, along with seeing the results of my effort is exciting. Thou, like most scientists know how important something like “error”is.  Experiments aren’t perfect, and ours requires a lot of work to ideal data. There are times we have a lot of experimental output showed up as “impossible” or “error” values, which makes me, even more encouraged to not giving up! Now, I’m starting to understand all of this jargon behind all of these complicated texts and codes.I look forward to work on this research as much as possible and more time running our trials, importantly getting great results! In order to get to the final goal it requires step by step to figuring it all out !