Physicists’ review paper on quantum transport could pave the way to improved energy management at the nanoscale

14 Feb 2023 Engineering Product Development Atomic, Molecular, Particle Physics

SUTD - Dario Poletti 
Instituto de Física da Universidade de São Paulo - Gabriel T. Landi
Helmholtz-Zentrum Dresden-Rossendorf - Gernot Schaller

The insights from the review could lead to the innovation of novel materials and devices to manage and control transport at the nanoscale.

The quantum effects of physics have become increasingly important in the advancement of communications, computing and sensing in speed, power and precision like never before. 

Through quantum mechanics, we can study the quantum effects - the physics of the transportation of intricate quantities such as particles, magnetisation and energy. In doing so, this can potentially spur the development of novel and powerful nanoelectronics such as thermal diodes. 

The field of quantum transport has been well established, with about 100 years of research efforts that have been invested into advancing the discipline. However, the vast amount of available data as well as the complexity of the systems make it an arduous task to review and assess the information.

To bridge this gap, researchers from the Singapore University of Technology and Design (SUTD) collaborated with Instituto de Física da Universidade de São Paulo and Helmholtz-Zentrum Dresden-Rossendorf to publish a review paper titled, ‘Non-equilibrium boundary-driven quantum systems: models, methods and properties’, and provided an overview of the theoretical understanding of quantum systems. Their paper was published in the Reviews of Modern Physics. 

"While a significant amount of research has been undertaken, the information has not been clearly organised. This makes it difficult for the research community to provide relevant contributions, share common pitfalls and may discourage potential researchers from entering the field. This review provides students and experts alike with the accessibility to better structured information, allowing for deeper insights that could in turn foster more research innovations," said principal investigator Associate Professor Dario Poletti from SUTD. 

The review focuses on nanoscopic systems, which at their extremities coupled with the environment in a way that a current could be forced to go through them. It is sectioned into three parts, reviewing how to model quantum transport setups, how to study them with analytical or numerical methods, and what is the phenomenology to be expected. In particular, the pros and cons of the models and methods were discussed. 

Assoc Prof Poletti also explained that the main results in key setups were assessed, laying the ground for anyone in the field of quantum transport, even those who are just starting out, to share on what has been done, where to find more detailed information, what were the long-standing open problems and how one could try to address them.  

"This review will further empower the research community to ask the most pressing questions and tackle the most important issues in quantum transport. Consequently, we will be able to figure out better energy management at the nano scale which can, in turn, create a more sustainable future for us," added Assoc Prof Poletti.

We thank the referees involved in the peer-review process for the detailed and constructive reports, which helped us to significantly improve the quality of this review. We also thank B. K. Agarwalla, V. Balachandran, G. Benenti, B. Buča, A. Eckardt, J. P. Garrahan, J. Goold, C. Guo, Z. L. Lim, J. J. Mendoza-Arenas, E. Pereira, T. Prosen, A. Purkayastha, L. Sá, A. Scardicchio, D. Segal, P. Stegmann, S. R. Taylor, J. Thingna, X. Xu, and M. Žnidarič for feedback on early draft of this review. We thank, in particular, J. J. Mendoza-Arenas and M. Žnidarič for sharing their data for Fig. 12. D. P. acknowledges support from the Ministry of Education of Singapore AcRF MOE Tier-II (Projects No. MOE2018-T2-2-142 and No. MOE-T2EP50120-0019). G. S. acknowledges support from the Helmholtz high-potential program and previous support from the DFG (Project No. 278162697-CRC 1242). G. T. L. and D. P. acknowledge the financial support and hospitality of the International Centre for Theoretical Physics (ICTP) in Trieste, Italy, where this project began.

'Non-equilibrium boundary-driven quantum systems: models, methods and properties', Reviews of Modern Physics. (DOI: 10.1103/RevModPhys.94.045006)