[QEI SEMINAR] Today at 15h CET !
The QEI online seminar series is back !
After almost a year without seminars, we come stronger than ever with this invitation to listen to Dr. Juliette Monsel, from Chalmers University, in Sweden, talking about her works in thermodynamics. It will happen on the 17th of February at 15h, on Zoom !
Title: Energetic cost of work extraction and information erasure
Speaker: Juliette Monsel (Chalmers University)
Abstract: Performing any useful task always comes at a cost and quantum thermodynamics provides tools to quantify it in nanoscale devices. In this seminar, I will focus on two specific tasks: The first one is work extraction, relevant in the context of, e.g., quantum heat engines or quantum batteries, and the second is information erasure, encountered in Maxwell-demon-based engines but also quantum and classical computing.
In the first part, I will analyze work extraction from a qubit into a waveguide acting as a battery, where work is the coherent component of the energy radiated by the qubit. The process is stimulated by a wave packet whose mean photon number (the battery's charge) can be adjusted. I will show that the extracted work is bounded by the qubit's ergotropy and that the bound is saturated for a large enough battery's charge. If this charge is small, work can still be extracted. Its amount is controlled by the quantum coherence initially injected in the qubit's state, which appears as a key parameter when energetic resources are limited [1].
In the second part, I will focus on the energetic cost of erasing a bit of information, which was fundamentally lower bounded by Landauer, in terms of the temperature of its environment. However, in real electronic devices, the information-bearing system is usually in contact with two or more electrodes, with different temperatures and chemical potentials. It is therefore not clear what sets the cost of erasure in such nonequilibrium situations. I will consider here a quantum dot, in which a bit is encoded in the presence or absence of a single electron. I will present a thermodynamic description of devices of this type, showing that, in addition to the electrode temperatures, the potential difference across the quantum dot and lifetime broadening of its energy level contribute to the minimum work cost of erasure. In practical contexts, these contributions may significantly outweigh the cost due to temperature alone. [2]
Date/Time: 17/02 at 3 pm CET (1hour) (10pm in Singapore, 9am in New York, 11am in Buenos Aires)
Zoom Link : https://lnkd.in/dtv9DSSW ( Meeting ID: 848 4993 6442, Passcode: 097310)
As always, the talk will be recorded and uploaded on our QEI YouTube Channel.