The second edition of the CECAM workshop will unite prominent experts and developers from three pivotal quantum transport communities: those working with the Non-equilibrium Green’s Functions (NEGF) [1] [2], those utilizing quantum phase-space methods [3] [4], and researchers specializing in developing efficient methods to reduce computational cost. This edition will place a strong focus on increasing female participation, acknowledging the underrepresentation of women in this area and striving to create a more inclusive and balanced environment for all participants. As we continue to push the boundaries of quantum transport research, it is vital to unite these distinct communities to tackle the multiscale challenges posed by nonequilibrium quantum transport in the next-generation nano-devices, especially when extending beyond the electron transport phenomena. 

The workshop will not only explore the latest developments in these fields but it will also reflect on the significant advancements made since the previous edition. We aim to foster an exchange of ideas, building on progress and incorporating new methodologies that further enhance our ability to simulate complex quantum systems efficiently.

This year’s focus will be on interdisciplinary collaboration. Specifically, encouraging contributions that highlight breakthroughs in simulation speed optimization, such as innovative coding techniques, numerical algorithms, and methods to reduce computational time. We seek to gather experts from diverse areas to discuss how these advancements can intersect, driving the development of powerful, next-generation quantum transport simulators.  

Key topics of discussion at the workshop will include:

• Recent advances in (semi-)empirical and ab initio NEGF
• Current developments in quantum phase-space techniques (Boltzmann and Wigner)
• Applications beyond electron transport, including thermal transport
• Efficient numerical methods and algorithms to enhance simulation performance

By bringing together experts from these three communities, the workshop will generate fresh insights and inspire novel approaches. All quantum transport methods face similar challenges, including improving the precision of physical models, expanding simulation domains, reducing computational costs, going beyond electronic applications, and transitioning from steady-state to transient simulations. In this context, we aim to explore how these different approaches can learn from one another, catalyzing more synergistic developments and strengthening our collective capabilities.

Our primary goal is to demonstrate the complementary strengths of NEGF, phase-space, and simulation efficiency techniques, and to explore how these methods can be integrated into the next-generation, multifunctional, multi-scale simulators. We will also discuss how to leverage the advances made since the last workshop to push the field forward.

The second edition of the CECAM workshop on “Quantum Transport Methods and Algorithms: From Particles to Waves Approaches” will address several critical questions, such as: 

• Can valuable information be shared between a NEGF solver and a Wigner solver (parameter coupling)?
• Is it possible for wave function (NEGF) and particle (Wigner) representations of carriers to coexist within a single simulation domain (tight coupling)?
• Can the semi-classical Multi-Subband Monte Carlo approach be extended to a purely quantum transport tool including the Wigner formalism (as both are particle based)?
• Are there applications that can only be tackled by one approach and not the others? Could new developments fill these gaps?
• Can we identify a common set of parallel numerical algorithms (eigenvalue, sparse linear, banded solvers, or stochastic methods)?
• Which numerical methods, apart from parallelization, or development characteristic could reduce the simulation time as the complexity is increased?
• What are the next big breakthroughs in quantum transport modelling?

As the semiconductor industry continues to demand advanced quantum transport tools that can compete with classical drift-diffusion models, this workshop marks an important step towards creating new simulation frameworks that meet both academic and industrial needs.