Microelectronics and Quantum Chip Modeling
What is ARTEMIS?
ARTEMIS (Adaptive mesh Refinement Timedomain ElectrodynaMics Solver) is a timedomain electrodynamics
solver developed in CCSE that is fully opensource and portable from laptops to manycore/GPU exascale
systems. The core solver is a finitedifference timedomain (FDTD) implementation for Maxwell's equations
that has been adapted to conditions found in microelectronic circuitry. This includes spatiallyvarying
material properties, boundary conditions, and external sources to model our target problems. In order
to achieve portability and performance on a range of platforms, ARTEMIS leverages the developments of
two DOE Exascale Computing Project (ECP) code frameworks. First, the AMReX software library is the
product of the ECP codesign center for adaptive, structured grid calculations. AMReX provides complete
data structure and parallel communication support for massively parallel manycore/GPU implementations
of structuredgrid simulations such as FDTD. Second, the WarpX accelerator code is an ECP application code for
modeling plasma wakefield accelerators and contains many features that have been leveraged by ARTEMIS.
These features include core computational kernels for FDTD, an overall time stepping framework, and I/O.
Using the ARTEMIS pythonstyle function interpreter, we can define more advanced structures containing
many different material types using different geometrical configurations. Additionally, the
GPU capability of the code provides extreme speed, as a GPU build offers a 59x speedup over the host on
a nodebynode basis. Thus, using HPC resources will allow for highresolution and rapid prototyping of
various configurations with different geometries and material properties. We also note algorithmic flexibility
for additional physics such as magnetic and superconducting materials.

ARTEMIS is part of the two DOEfunded MicroelectronicsCoDesign programs at Berkeley Lab
(Click here for the full list of awards) .
Overview of the devicelevel modeling capability, the ARTEMIS package.
ARTEMIS bridges the gap between material physics and circuit model of PARADISE, by solving governing PDEs of the physics in devices such as NCFET and MESO.
Since ARTEMIS is based off two ECP products, AMReX and WarpX, it fully functions on GPU supercomputers such as NERSC CORI system, providing rapid devicelevel modeling to the codesign workflow.
For more information about ARTEMIS or any of the applications below, contact the
ARTEMIS Team
or visit the ARTEMIS github page.

Spin Dynamics
The trend of technology in recent years has been towards miniaturization and interconnection.
Continuous scaling down of circuitry is pushing Moore's law in the semiconductor industry nearly to
an end and has entailed novel materials and new techniques to generate nanoscale devices with desired
performance. Such new materials and techniques usually involve multiple physical mechanisms. For
instance, one of the thriving techniques is to use magnetic spins to control and manipulate
electromagnetic (EM) signals in radiofrequency (RF) circuitry, with exceptional scalability and low
power dissipation. The corporation of new mechanism also enables things like quantum computing.
However, the stateoftheart design of RF magnetic devices has been hindered mainly by the lack of
effective modeling tool to tackle the interaction between oscillating magnetization and EM waves.
This problem is primarily due to the inherent disparity in time and length scale between magnetic
spin oscillations and EM waves. Hence, in order to fully understand the underlying physics and design
the nextgeneration devices, a new multiphysics modeling approach is needed.
We are using new physical coupling in potential electronic devices. This includes modeling and
characterization of miniaturized magnetic components in radiofrequency (RF)
systems, specifically nonlinear dynamic magnetic spin oscillations interacting with EM waves. We are
developing a unique numerical algorithm to predict the influence of magnetic spins on the performance
of compact RF devices. The Development of this multiphysics software is under the framework of
AMReX,
with features of massively parallel computing and blockstructured adaptive mesh refinement (AMR).
Such modeling tools enable a unique ability to accurately model and design
nextgeneration RF systems and components.
Classical Modeling of Quantum Chips
In an effort to aid in the design of better quantum chip prototypes,
we are developing a new numerical modeling capability to predict both
the interaction between qubits and photons (known as circuit quantum electrodynamics, or cQED)
and the crosstalk between qubits and inair electromagnetic (EM) waves.
This requires implementation of new physical models to resolve the nonlinear interactions
between the EM field and the quantum response from the Josephson junction modeled using a
hybrid classicalquantum approach. Additionally, to model the photonqubit interaction,
the Maxwell's equations will be implicitly coupled to the Schrodinger equation
that quantifies the qubit response to the applied and selfconsistent EM field.
With the use of adaptive mesh and adaptive algorithm approach for this complex
electrodynamic material model with a complex embedded geomtry,
we will be able to conduct a detailed numerical study on the loss mechanisms for a given quantum chip prototype.
NanoSensors on CMOS
As traditional CMOS scaling offers diminishing gains in performance, alternative approaches, such as codesign
and heterogeneous integration of lowdimensional (0D, 1D and 2D) materials, present new opportunities.
We are developing scalable integration of photon nanosensors on a CMOS platform.
CMOS circuit simulation is an indispensable part of any modern design. Manufacturers provide extremely
detailed simulation models for the devices in their process, to be used with specific circuit simulators. These
are generally based on SPICE for the lowest level simulations that are carried out. Incorporating new active
devices that will be part of the same circuit along with CMOS transistors requires the same level of detail and
full compatibility with the commercial simulator codes used. While transistor models have typically been
extracted from parameter analyzer measurements on a large variety of device geometries and test conditions,
this approach would be prohibitive for initial modeling of new nanodevices, where generating a large variety
of test devices and making hundreds of measurements on each would represent a large effort and take a long
time. We will instead rely on physical modeling starting from the device structure using ARTEMIS.
Publications
Z. Yao, R. Jambunathan, Y. Zeng, and A. Nonaka,
A Massively Parallel TimeDomain Coupled ElectrodynamicsMicromagnetics Solver,
submitted for publication, 2021.
[arxiv]
