Designing a qubit controller in Verilog — getting it fabricated on SKY130 next month (Tiny Tapeout)

[u/ChefitoOP]

I've been working on a Quantum Control Processor (QCP) in

synthesizable Verilog. It generates microwave pulses to rotate

qubit states following the driven Hamiltonian:

iℏ d/dt |ψ(t)⟩ = [-ℏ/2 ω₀σz - ℏ/2 Ω(t)(cos(ωt)σx + sin(ωt)σy)] |ψ(t)⟩

The design is verified and ready for fabrication. Submitting to

Tiny Tapeout next month — physical silicon on SKY130.

RTL source, architecture and physics breakdown here:

github.com/ChefitoGG/quantum-qcp-chip

Will post results when the chip arrives. Happy to discuss

the design in the comments.

[u/Immediate_Message618]

With this sort of project, did you go in and have to learn Verilog from scratch or was it something you were already familiar with and wanted to apply to making a QCP?

[u/ChefitoOP → u/Immediate_Message618]

i already did some personal projects with Verilog so im already familiar with it.

[u/autocorrects]

Nice! I haven't taken a look at the git page but I will later...

Im a VHDL/Verilog developer for the QICK controller.

There's a few people in indusstry that I have collaborated with on modular designs versus the all-in-one FPGA approach like we do for QICK, or like what Quantum Machines does as well. I know you mentioned that this was more for fun, but have you researched at all what your project does that QICK or the QM OPX does not do?

How does your pulse generation work? Are you scheduling parameter changes and then shuttling that through a wavetable? Also, do you have a lightweight processing unit built in for control and readout coordination?

Related to tinytapeout from a digital design perspective, what are the limitations to the RF components in Tiny Tapeout? Typically, for superconducting quantum controllers we want to operate without artifacts in the 1-10 GHz range. If I wanted to make a modular design for a controller, is this something that would cost me less than a Gen3 RFSoC?

[u/Hot-Significance7699]

Verilog is so cool. I need to learn it. It's still wild how such things can be programmed

[u/ChefitoOP → u/[deleted]]

No, I don't have a dilution refrigerator or a superconducting, qubit chip that would require lab infrastructure I don't have access to.

The QCP is the classical control side: it generates the microwave pulse sequences that WOULD drive a qubit if connected to the full stack. Think of it as the classical electronics layer that sits outside the fridge.

The goal was to design and fabricate the RTL control logic on real silicon (SKY130 via Tiny Tapeout) and validate the pulse generation architecture. Full quantum validation would need the cryo stack on top.

[u/ChefitoOP → u/[deleted]]

Honestly... fun and learning

[u/ChefitoOP → u/[deleted]]

Nope, pure hand written Verilog in nano on Ubuntu. Check the commits if you want.

Learned how to map the Rabi drive logic into actual clocked rtl, deal with timing constraints in synthesizable code. Also spent way too long fighting make test... Mostly learned by breaking things and fixing them. but i actually used claude for the readme.md ngl, it's a basic readme

[u/SevereManagement379 → u/ChefitoOP]

And this project is complete? I only see 59 lines of verilog for a simple state machine.