SemiWiki.com - Video EP11: Meeting the Challenges of Superconducting Quantum System Design with Mohamed Hassan

Episode Date: November 7, 2025

In this episode of the Semiconductor Insiders video series,  Dan is joined by Mohamed Hassan, who leads the Quantum EDA segment at Keysight. Mohammed provides a broad overview of superconducting quantum system design. He discusses the challenges for this design style and how EDA requirements for quantum design differ from… Read More

Hello, my name is Daniel Neni, the founder of Semewiki, the Open Forum for Semiconductor Professionals. Welcome to the Semiconductor Insiders video series, where we take 10 minutes to discuss leading-edge semiconductor design challenges with industry experts. My guest today is Mohamed Hassan. He leads the Quantum EDA segment at Kisite. Mohamed, what are the major components of a superconducting quantum system? Yeah, thanks to Daniel.

superconducting quantum systems consists of a system that being tested in a dilution fridge at near zero temperature colder than the outer space. And then over there, we will see the qubits being tested at the bottom stage of the dilution fridge near zero mili-kilven at 20 mili-kilven or so. And that's the heart of the system. And then being read out by a quantum amplifier to combat the noise and improve the readout fidelity what are the main design challenges for superconducting quantum systems yeah great question so mainly that you know the development cycle is very complex long and costly because of the size of the problem it's electrically very large when you go to very large number of cubits we face so many challenges because of the size of the

problem. Same thing also for quantum amplifiers, especially the traveling wave ones, is pretty large, complex layout, minute co-planar wave guide features, and cross-stock also is one of the major challenges. On top of that, you know, microve engineers face this steep learning curve at the beginning when they jump to the quantum field. So all of this makes the development pretty complex. Right. So how do EDA requirements for quantum computers different from those for classical devices like cell phones or a laptop? Yeah, I like that question. So we believe at Keyside that quantum computers eventually will evolve and mature such that their design will be more or less similar to an established cell phone design cycle where you have circuit, layout,

EM and system level design. In quantum, we have similar similarities there. We do need to do cubit design, device level modeling. We do need to do quantum amplifier design. We do need to do circuit layout and EM analysis. Top of that, we do also care about a lot about noise. And that's why we do need noise analysis. So for quantum computers, I always say let's go where photons go compared to cell phones where, you know, we look after signals. And what EDA solutions does Kiesat offer for superconducting quantum systems? Yeah, as of today, with that in mind, the mindset of like, you know, let's do something similar to cell phones, we have an established workflow that goes between layout, EM, circuit, and system.

And this is pretty similar to established microwave systems where, you know, after layout, you do layout validation in the EM environment, and you move to circuit analysis and do co-simulation between layout, between EM and circuit, and then eventually move to systems. So for quantum today, we have a layout solution in our EDS platform. We do have quantum pro for EM analysis, and we do have quantum. circuit same for quantum circuit and it takes into account the peculiarities of quantum circuits like flux quantization for instance and like four weeks ago also we just released also a system solution that enabled peoples to virtually test their quantum chips what makes quantum pro unique in the quantum eda market yeah quantum pro is the em solution and what's unique about it that

this is the first ever integrated solution that can take things end to end from circuit, layout, electromagnetic analysis, quantum parameter extraction, which is fully automated, and that talks to the barrier for microwave engineers. So we're lowering that barrier for microwave engineers. And then after finalizing the EM simulation, we can also pivot towards the circuit environment and do co-simulation, take into account the the non-linearities in the system and so on, so forth. Can you describe the typical workflow for designing superconducting quantum chip using these tools? Absolutely.

Yeah. So we envision that the workflow will look like this. You start from a schematic where you have some conceptual design. You start building the schematic from the library of components that we have in EDS. And this is more less like a Lego. you start building from it the chip and the schematic that's my favorite place for building chips and then from the schematic you generate the layout it's which is very straightforward in edis just a bush of a button after layout and once we're happy regarding the buildup of the layout we move in the EM environment and then we over there in quantum pro we have access to two great numerical techniques method of moment and finite element method method method of moment is a has a you know surface mesh finite element method has a volume mesh so method of moment often faster for planner structures

we also have kinetic inductance of superconductors and EM environment which is very critical for quantum applications once we solve in the EM environment we automate we can with a bush of a button automatically extract quantum parameters, and that's colorful tables that you see top left, which includes the Hamiltonian of the system, and that's exactly the goal of the simulation. We're optimizing the layout to meet certain requirements for quantum parameters, and that way we can iterate on the workflow until the designer is happy about designed quantum parameters. And can you share a real world success story using these EDA tools? Absolutely.

So this one is really I'm proud of. We did it in collaboration with Google Quantum AI team, one of our customers. They came to us with a problem that they have what they call a snake. It's an array of superconducting loops, but that array is particularly large, as they're can see in that schematic in the screen and they were trying to capture the inductance of the array taking into account the end effects as you can still from the schematic the ends of the array is not the same like the middle one the middle pieces of the array and that took some significant work because of the peculiarities of superconducting loops that

you know, they display what we call flux quantization, that the flux is quantized in the circuit. What we did with them is that we found a very clever way of doing the flux quantization in a language or in a way that the circuit solvers can understand, and that's that auxiliary loop on the left side. And with that way of implementation, we can map the flux quantization to Kirchiev voltage law. And then with that way, we were able to. to capture the uniqueness of flux quantization in their array and produce really fantastic results that were published in IEE applied support conductivity

earlier this year. Very interesting. Great conversation, Muhammad. Thank you for your time. Yeah, great. Thanks a lot, Daniel, for inviting me. I enjoyed the conversation as well. That concludes our video.

Thank you for watching and have a nice day. Thank you.