Peter Kraus

Vrije Universiteit (VU) Amsterdam, Advanced Research Center for Nanolithography (ARCNL), Netherlands

Towards ultrafast imaging of correlated matter with transient high-harmonic generation

When: 12:00-13:00 CET, October 1st (Tuesday), 2024

Where: Main Hall, ICMM-CSIC, Campus de Cantoblanco, Madrid

The highly complex collective electron-dynamics in strongly correlated materials mandates experimental techniques with sub-fs temporal and nanometer spatial resolution. While a plethora of techniques exists, true nanometer imaging on fs or even sub-fs timescales remains elusive. Such techniques are required to follow the collective dynamics of electrons in strongly correlated materials in real time, which drive ultrafast phase transitions that are accompanied by technologically relevant order-of-magnitude resistivity switches.
High-harmonic generation (HHG) in solids has emerged 14 years ago. Gas-phase HHG is highly sensitive and thus optically controllable with regards to the microscopic generation
mechanism. The parallels between solid and gas-phase HHG suggest that solid-state HHG may be controlled in a similar manner, which enables a generally applicable all-optical light switch with wide application potential. The current literature on transient solid-state HHG confirms this opportunity of all-optical control of solid HHG [1]. In this talk, I will present our vision to use this light switch for sub-fs super-resolution nanoscale imaging by HHG from correlated materials. In particular, I will present three key experiments on our roadmap towards this goal.
On the nanoscale, we controlled HHG via engineering the surface topography of solids, which in turn demonstrates how solid HHG can be used for metrology on surfaces and tailored as a light source [2-4].
On the femtosecond time scale, we used the sensitivity of HHG to electronic band structure to follow ultrafast phase transitions in strongly correlated materials [5], and photocarrier dynamics in perovskites [6]. While the first measurements [2] showed nanoscale sensitivity, the second set of experiments [5,6] demonstrated that photoexcitation can be used to control light emission via solid HHG.
Combining both efforts, I will show first results how ultrafast control of solid HHG enables
HArmonic DEactivation microScopy (HADES) – a label-free super-resolution microscopy
below the diffraction limit of light [7]. Thinking ahead, the development of these techniques may enable resolution on the nanometer and femto- to attosecond scale fitted into a regular microscopy setting, with application potential ranging from strongly correlated materials to semiconductor metrology, photosynthetic processes, and medical imaging.

References:
[1] P. v. Essen, Z. Nie, B. de Keijzer, P.M. Kraus, arXiv:2402.15375, ACS Photonics, accepted  (2024).
[2] S.D.C. Roscam Abbing, R. Kolkowski, Z.-Y. Zhang, F. Campi, L. Loetgering, A.F. Koenderink, P.M. Kraus,
Physical Review Letters 128, 223902 (2022).
[3] P. M. Kraus et al., US Patent App. 18/038,590 (2024).
[4] P. M. Kraus et al., US Patent App. 18/253,734 (2024).
[5] Z. Nie et al., Peter M. Kraus, Physical Review Letters, 131, 243201 (2023).
[6] M. v.d. Geest, J.J. de Boer, K. Murzyn, P. Juergens, B. Ehrler, P.M. Kraus, Journal of Phys. Chem. Lett., 14, 10810 (2023).
[7] K. Murzyn, M.v.d. Geest, L. Guery, Z. Nie, P.v. Essen, S. Witte, P.M. Kraus, arXiv:2403.06617, submitted (2024).

Miguel Bastarrachea-Magnani

Universidad Autónoma
Metropolitana-Iztapalapa

Quantum probing of classical structures in the Dicke Hamiltonian

When: 12:00-13:00 CET, November 21st (Thursday), 2024

Where: Seminar Room (182), ICMM-CSIC, Campus de Cantoblanco, Madrid

The Dicke Hamiltonian is a paradigmatic model of quantum
optics that describe the ultra-strong coupling between light and
collective modes of matter. This interaction results in the creation of
polaritons, hybrid quantum states that share properties of their
original components. Originally proposed to describe atoms in cavities,
the model has now become a general formulation of the spin-boson
interaction with applications in polariton physics and various systems
within the context of quantum information, atomic physics, and condensed
matter. In this talk, I will address the model’s theoretical richness
for exploring the quantum-classical correspondence. Thanks to its
collective nature, it is possible to easily identify a classical
counterpart and use quantum localization techniques to probe, identify,
and quantify structures in phase space, regularity, and chaos,
establishing a route to explore other, more complex, interacting quantum
systems.

Gerhard Klimeck

Purdue University, West Lafayette, IN 47907, USA

From Atomistic, Non-Equilibrium Quantum Statistical Mechanics Theory
to Today’s Transistor Design and Global Impact – A 25-Year Journey

When: 11:00-12:00 CET, September 18th (Wednesday), 2024

Where: Seminar Room (182), ICMM-CSIC, Campus de Cantoblanco, Madrid

30 years ago, the appropriate quantum transport theories, basis sets, algorithms, user interfaces, and dissemination methods for quantum device modeling were subjects of intense debate and uncertainty. The development of the Nanoelectronic MOdeling (NEMO) toolset commenced in 1994 at Texas Instruments, continued in 1998 and NASA/JPL, and has been ongoing at Purdue since 2004. Modern nanoscale transistor design extensively employs advanced quantum transport modeling tools, representing physical devices in three dimensions with atomistic basis sets. The NEMO implementations of the Non-Equilibrium Green Function (NEGF) formalism with atomistic tight-binding basis have become the benchmark for quantitative and predictive device simulation. This methodology has now been widely adopted by most device modeling research teams. In 2015, Intel integrated NEMO5 into their in-house design suite, utilizing a top-100 ranked supercomputer for design explorations [1]. Silvaco initiated commercialization efforts [2] in 2018, with industry leaders such as Samsung and TSMC developing their in-house solutions based on NEMO. NEMO’s capability to accurately model crystal orientations and strain in complex systems facilitated the development of Texas Instruments’ rotated substrate technology in 2004 [3], significantly impacting chips used in billions of cell phones. Contemporary 3D FinFETs [4] and nanosheet transistors share the 5 nm central length characteristics with 1D resonant tunneling diodes (RTDs). The quantitative and predictive modeling of 1D RTDs (1994-1997) established the standards necessary for today’s 3D nano-transistors.

NEMO’s applications extend beyond usage by experts equipped with specialized computational hardware. Over 25,000 users on nanoHUB.org, the pioneering comprehensive scientific computing cloud platform, have investigated various nanoscale devices such as nanowires, ultra-thin-body transistors, and quantum dots utilizing the intuitive NEMO/OMEN tools. These tools are supplemented by straightforward applications, rendering them accessible to a broad spectrum of users. Notably, more than fifty percent of nanoHUB’s simulation users participate in formal educational settings across 1,000 institutions globally, immersing themselves in device exploration and modeling principles. nanoHUB hosts 700+ apps and tools, along with over 170 courses.

This presentation will provide an overview of the critical physical phenomena needed to be captured for realistic device design, how high-performance-computing can deliver results to engineers & students, and how NEMO has been deployed on nanoHUB.org.

This work would not have been possible without my hundreds of collaborators who helped to build, test drive, break, and rebuild NEMO/OMEN [5-9,12-14] and nanoHUB [10,11].  I have the deepest appreciation for their hard work, dedication and in most cases their personal friendship. The citations here just cover some of the fundamental developments. Citations to these papers lead to hundreds of publications enabled by my collaborators and friends.

[1] Mark Stettler et al., IEDM, 39.1.1 (2019)
[2] Silvaco – Victory Atomistic, silvaco.com
[3] RC Bowen et al., US patent 7,268,399 (2004)
[4] G. Yeap et al., IEDM, 36.7.1 (2019)
[5] G. Klimeck, et al., APL Lett. 67, 2539 (1995)
[6] RC Bowen, et al., JAP 81, 3207 (1997)
[7] Jing Wang, et al., APL. 86, 093113 (2005)
[8] M Luisier, et al., Phys. Rev. B 74, 205323 (2006)
[9] G Klimeck el al, Superlatt. and Microstr., 27, 77, (2000)
[10] G Klimeck, et al, IEEE CISE, Vol. 10, 17 (2008)
[11] M. Hunt et al, PLoS ONE 17(3): e0264492.
[12] R Lake, et al.,JAP 81, 7845 (1997)
[13] G. Klimeck, et al, Computer Modeling in Engineering and Science (CMES) 3, 601-642 (2002).
[14] S Steiger et al., IEEE Tr. Nanotechn., 10, 1464, (2011)