Project Logs

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• I Saw a Real Superconducting Quantum Computer Chip

  S.I. • an hour ago • 0 comments

  Hi everyone! I’m a KOSEN student building a DIY EFNMR Quantum Computer.

  In this log, I want to take a quick break from our DIY hardware to share a personal story about the time I visited the National Museum of Emerging Science and Innovation (Miraikan) in Tokyo to see a real superconducting quantum computer chip on display.

  My Trip to the Miraikan

  "Under Maintenance!?"

  Right after graduating from middle school, during my spring break, I had some free time. I had been wanting to see a real quantum computer chip for a long time, so I went to the Miraikan. The moment I arrived, I made a beeline for the quantum computer exhibit. However, right where the chip was supposed to be displayed, there was a sign that said, "Under Maintenance." I was honestly a bit heartbroken.

  Despite that, the rest of the exhibits at the Miraikan were incredibly fascinating. Even without seeing the quantum chip, I ended up staying there all day, from opening until closing time! The highlight of that trip was the dome theater showing a movie called "The Man from the 9 Dimensions," which was an amazing visual exploration of Superstring Theory.

  Finally Seeing the Chip!

  Fast forward to this summer break: I went back to the Miraikan for my revenge (?). Just like last time, I headed straight for the quantum exhibit. And this time... the chip was actually there!

  I was incredibly excited to finally see the superconducting quantum chip I had been dreaming about. My first impression upon seeing the real thing? It was much smaller than I expected! I had always imagined it would be around 5cm square, but it was actually only about 3cm square.

  By the way, I watched "The Man from the 9 Dimensions" again on this trip! I went on a weekday afternoon in September, and it was surprisingly crowded (maybe because the museum is about to close for a 6-month renovation?). Seeing the real hardware up close gave me a huge boost of motivation to keep working on my own DIY quantum computer on my desk!

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  Follow Our Journey!

  • Real-time updates on X (Twitter): https://x.com/nmrqcproject
  • Detailed development logs and source code on GitHub: https://github.com/nmrqcproject/nmr-qc-project/blob/main/README.md
  • Detailed development logs in Japanese / 日本語での詳しい開発記録 (Zenn): https://zenn.dev/nmrqcp

• Noise Reduction Strategies

  S.I. • an hour ago • 0 comments

  Hi everyone! I’m a KOSEN student building a DIY EFNMR Quantum Computer.

  In this log, I want to share the 7 hardware upgrades and noise reduction strategies we are planning to implement next in order to clean up our FID signal.

  1. Sealing the Aluminum Shielding Enclosure

  Currently, because we have cables running in and out of the aluminum case, we can't close the lid completely. Environmental noise is leaking through this gap. The best solution is to drill small, exact-sized holes in the enclosure for the cables to pass through. Drilling is a bit of a last resort because it's difficult, but it's the most effective way. Another option is sealing the gap with aluminum tape, but peeling it off every time we need to tweak the circuit would be a nightmare.

  2. Migrating the Amp from Breadboard to Perfboard

  Right now, our ultra-low noise amplifier circuit is built on a breadboard. However, the breadboard itself acts as a giant antenna, picking up noise and feeding it straight into the op-amp. To fix this, we will permanently solder the amp circuit onto a universal PCB (perfboard).

  3. Adding an Analog High-Pass Filter (HPF)

  We plan to physically filter out low-frequency environmental noise before it even reaches the ADC. We will build an analog High-Pass Filter (HPF) using film capacitors and resistors directly into the amplifier circuit.

  4. Coaxial Shielding for the Coil-to-Amp Connection

  We are currently using standard jumper wires to transmit the microscopic signal from the sensor coil to the amplifier. We will replace these jumpers with shielded coaxial cables to block electromagnetic interference (EMI) during signal transmission.

  5. Twisting the Polarization Battery Cables

  The thick cables running from the 12V lead-acid battery to the polarizing coil are currently just bundled together. When a massive current flows, they generate their own magnetic field, causing internal noise. We will twist the positive and negative cables together (creating a twisted pair) to cancel out the emitted magnetic fields.

  6. Adding a Relay to the Polarization Circuit

  Currently, the high-current polarization circuit is controlled solely by a MOSFET. By integrating a mechanical relay into the circuit, we will be able to physically isolate and disconnect the polarization circuit from the amplifier during the highly sensitive receiving phase.

  7. Changing the Measurement Location (Going Outdoors!)

  For our recent successful FID observation, we measured in a room with relatively stable magnetic fields. However, a room is still inside a building—surrounded by rebar concrete and electronic devices emitting noise. To eliminate these sources entirely, we plan to pack up the system and run the experiment outdoors in a wide-open park!

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  Personal Note: The Real Fun Begins!

  Now that we’ve entered the noise-reduction phase, this project feels more like real quantum computing than ever! Noise is one of the biggest hurdles in cutting-edge quantum computer development right now. This is where the real struggle—and the real fun—lies. To achieve my dream of becoming a quantum hardware developer, I am going to grind through these noise countermeasures and level up my engineering skills!

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  Follow Our Journey!

  • Real-time updates on X (Twitter): https://x.com/nmrqcproject
  • Detailed development logs and source code on GitHub: https://github.com/nmrqcproject/nmr-qc-project/blob/main/README.md
  • Detailed development logs in Japanese / 日本語での詳しい開発記録 (Zenn): https://zenn.dev/nmrqcp

• Our Concept and Our Catchphrase.

  S.I. • an hour ago • 0 comments

  Hi everyone! I’m a KOSEN student building a DIY EFNMR Quantum Computer.

  In this log, I want to share the origin of our project name, the meaning behind our logo, our core concept, and our newly created catchphrase.

  Origin of the Project Name

  NMRQCP

  This is both my profile name and the official name of our DIY quantum computer project. NMRQCP comes from the initials of "Earth's Field Nuclear Magnetic Resonance Quantum Computer" (EFNMRQC). Since EFNMRQC was a bit too long, we dropped the "EF" to make it NMRQC, and added a "P" for Project—resulting in NMRQCP.

  What Our Logo Represents

  This is the official logo of our project. The Bloch sphere in the background represents quantum computing and the manipulation of quantum states, while the waveform in the foreground represents the actual NMR signal (FID wave) that we capture and read with our EFNMRQC hardware.

  Project Concept

  Democratizing Quantum Computing

  This is the core concept driving our project. Right now, actual quantum computer hardware is locked behind closed doors—accessible only to massive corporations, research institutes, and universities. Our mission is to change that and make quantum hardware accessible to anyone.

  By developing a low-cost, easy-to-build quantum computer and open-sourcing all of the designs and code online, I want to help build a society where anyone can get hands-on experience with quantum hardware—a truly democratized quantum future.

  (If you want to read more about why I want to make this accessible to everyone and how I first got into quantum mechanics, check out our project details or this article (in Japanese).)

  Our Catchphrase

  "If it doesn't exist, we build it. Quantum Computers on your desk."

  The first half—"If it doesn't exist, we build it"—comes from my lifelong maker motto. I desperately wanted to touch and tinker with quantum computer hardware, but had zero access to it. This project was born out of that exact frustration: if there's no way for me to touch one, I'll just build one myself.

  The second half—"Quantum Computers on your desk"—captures the exact defining feature of this project: creating a quantum computer compact and accessible enough that anyone can build and run it right on their own desktop.

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  Follow Our Journey!

  • Real-time updates on X (Twitter): https://x.com/nmrqcproject
  • Detailed development logs and source code on GitHub: https://github.com/nmrqcproject/nmr-qc-project/blob/main/README.md
  • Detailed development logs in Japanese / 日本語での詳しい開発記録 (Zenn): https://zenn.dev/nmrqcp

• Observing the FID Signal!

  S.I. • an hour ago • 0 comments

  Hi everyone! I’m a KOSEN student building a DIY EFNMR Quantum Computer.

  In this latest experiment, we finally succeeded in capturing the FID signal (damped sine wave)!

  Observing the FID Signal!

  First, the FID signal of hydrogen atoms (protons) in the Earth's magnetic field occurs at a frequency right around 2000Hz to 2100Hz.

  If you look at the bottom graph in the photo, right around the purple dot between 2000Hz and 2100Hz, there is a distinct, sharp peak. This is the exact FID signal we’ve been hunting for!

  However, looking at the top time-domain graph, you can't really see a clear damped sine wave. We believe this is because a massive dead time is occurring in the green section due to residual surge current from the coil switching.

  This also explains why the peak around 2000Hz–2100Hz is relatively small. Because of the dead time, we are losing the initial head of the damped sine wave where the signal amplitude is at its strongest. What the FFT graph is actually showing is the tail end of the microscopic FID signal—those tiny oscillations right after the green dead-time line drops back to zero in the top graph.

  Future Challenges & Countermeasures

  This experiment brought two critical hardware challenges to light:

  • Due to dead time, we are missing the most crucial data right after sequence switching.
  • The signal is still nearly buried in analog noise.

  Personal Thoughts: A 6-Month Journey & The 0.25x Speed Discovery!

  I am beyond thrilled that we finally observed the FID signal! It took us about half a year to get to this point. For six months, spending hours every single day researching, brainstorming, building, and testing has finally paid off!

  This experiment was the very first time we ran all the circuits together and performed real data analysis. Funny enough, while we were running the experiment, I didn't even realize the FID signal had appeared. Because the signal flashes by in a fraction of a second, we were recording a video of the screen and playing it back at 0.5x speed—and we couldn't find anything. I thought we had failed.

  However, a little while after returning to my dorm room, I uploaded the video to Google Photos and rewatched it at 0.25x speed. Suddenly, I thought, "Wait... could this be it?!" I paused the video and scrubbed through it frame-by-frame manually—and there it was: the exact frame showing the FID peak on the graph! Going from the disappointment of thinking it failed to discovering we actually caught it made me unbelievably excited.

  Riding this momentum, we are going to keep tackling the dead-time and noise issues head-on and complete this DIY quantum computer!

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  Follow Our Journey!

  • Real-time updates on X (Twitter): https://x.com/nmrqcproject
  • Detailed development logs and source code on GitHub: https://github.com/nmrqcproject/nmr-qc-project/blob/main/README.md
  • Detailed development logs in Japanese / 日本語での詳しい開発記録 (Zenn): https://zenn.dev/nmrqcp

• [Archive] Project History & Early Development (Apr - Sep 2026)

  S.I. • an hour ago • 0 comments

  💡 Archived Development Logs: This post compiles the early records of our project (Chapters 01–14). Since I didn't have time to write massive foundational articles while building the hardware in parallel, I used AI to help structure the text for these early logs. (Starting from our latest log where we successfully observed the FID signal, everything is written 100% in my own words!)

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  01. What is a Quantum Computer?

  First, the computers inside our smartphones and PCs are called "classical computers."

  Differences from Classical Computers

  Simply put, quantum computers are orders of magnitude faster at specific calculations. For example, Google reported that their quantum computer (Willow) solved a calculation in 300 seconds that would take a supercomputer longer than the age of the universe (about 13.8 billion years). That makes it roughly 1.5 quadrillion times faster. However, quantum computers have strengths and weaknesses—they aren't faster at everything, and classical computers still beat them in many everyday tasks.

  What Can They Do? (Present & Future)

  Quantum computers excel at simulations and optimization, analyzing far more patterns than classical machines.

  • Current Applications: Optimizing delivery routes and factory production lines (Japan Post, Denso), financial simulations (MUFG), exploring stable chemical structures for drug discovery (PeptiDream, Fujitsu), and elucidating chemical reaction mechanisms (Mitsubishi Chemical).

  • Future Potential: Next-gen material discovery (more efficient solar panels, CO2 capture), molecular-level drug simulations with zero side effects, hyper-accurate weather forecasting, infrastructure optimization (solving traffic jams), artificial photosynthesis, breaking current cryptography (driving the shift to post-quantum cryptography), and advancing fundamental physics (I personally hope quantum simulations bring us one step closer to the "Theory of Everything").

  Timeline & What Students Should Do

  As of 2026, quantum computers are entering the practical phase, though still far from perfect. Near-complete machines are expected around 2030, and fault-tolerant general-purpose quantum computers around 2050. For students looking to dive in: start with an introductory book with good illustrations, attend quantum events to hear from experts in person, and try cloud quantum services like IBM Quantum to experience it firsthand!

  *Note: The illustrations in Chapter 01 were generated using Gemini.

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  02. Starting a DIY Quantum Computer Using the Earth's Magnetic Field!

  In April 2026, I officially started a personal project to build my own quantum computer! You might think a quantum computer requires a massive cryostat cooled to -273°C, but I am using a method called EFNMR (Earth's Field Nuclear Magnetic Resonance).

  Using the Earth Itself as a Giant Magnet

  While hospital MRIs and standard NMR machines use ultra-powerful superconducting magnets, our Earth itself is a giant magnet with a North and South pole. EFNMR uses this natural magnetic field to control nuclear spins (qubits). Because it needs no massive cooling system, you can observe and manipulate quantum mechanical phenomena right on your desk by building your own coils and circuits.

  What We Are Building (Full-Scratch)

  • Polarizing & Receiver Coil: Enamel wire hand-wound in many layers around a transparent PVC pipe holding a pure water sample.
  • Signal Processing Circuit: A custom op-amp amplifier inside an aluminum shielding enclosure to pick up nanovolt-to-microvolt signals.
  • FPGA: Dedicated digital circuitry for high-speed, precision pulse control.
  • Python: FID signal analysis, noise removal, and Fast Fourier Transform (FFT).
  • Power & Control: Lead-acid battery + MOSFET circuit to minimize power noise, controlled and monitored by an M5Stack.

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  03 & 04. Simulating NMR Signals in Python: FFT and Pulse Control

  Before touching the soldering iron, let's look at how we observe and manipulate...

  Read more »

• Building a Quantum Computer from scratch!

  S.I. • an hour ago • 0 comments

  Hi everyone, I’m a KOSEN (National Institute of Technology in Japan) student, and together with my friends, I am building a DIY Quantum Computer using the Earth's Field Nuclear Magnetic Resonance (EFNMR) method. In this log, I’ll share the backstory of how I ended up building a quantum computer from scratch and give an overview of the project.

  The Origin Story: Why I Decided to Build a Quantum Computer

  My First Encounter with Quantum Mechanics and a Middle School Science Project

  I first learned about quantum mechanics when I was in my second year of middle school (8th grade). I was immediately captivated by the fact that, despite how surreal and counterintuitive quantum theory seems, it is the very foundation of how our world operates. Driven by this fascination, I conducted a science project measuring the width of slits by performing a double-slit experiment using everyday items (a CD, a holographic card sleeve, and a screen privacy filter).

  Later, I read a book about "Quantum Supremacy," which introduced me to quantum computers. The idea of fusing my love for quantum mechanics with my passion for making things (hardware DIY) completely hooked me. In my third year of middle school, I used the IBM Quantum Composer to verify quantum algorithms for another project. It was then that I decided I wanted to become a hardware engineer for quantum computers in the future.

  The Hardware Wall: Lack of Access

  While I was able to get my hands on the software side of quantum computing, the hardware—which I am far more interested in—was completely out of reach. Aside from facility tours, there was almost zero opportunity to actually touch or interact with it. Since I was a kid, my motto has always been: "If it doesn't exist, build it." So, in middle school, I looked into whether I could build a quantum computer myself. However, I found out it would cost a minimum of 300,000 JPY (around $2,000), which forced me to give up at the time.

  Discovering the EFNMR Method

  After enrolling in KOSEN, I was determined to take some kind of action regarding quantum computers. I obsessively researched DIY quantum computing again and discovered that by using the Earth's Field Nuclear Magnetic Resonance (EFNMR) method, I could start a project for about 100,000 JPY (around $700).

  Knowing this was my chance, I fully committed to building an EFNMR quantum computer. I immediately dove into the details and started by simulating the signals using Python.

  EFNMR Quantum Computer Project Details

  Operating Principle

  1. Spin Initialization (Polarization): We run a massive current through a large coil to align the proton spins (in pure water) with the magnetic field, setting the qubit to the |0⟩ state.
  2. Sequence Switching: Using a MOSFET and a relay unit, we switch the circuit between the high-current coil phase and the highly sensitive signal-reading phase.
  3. Signal Amplification: When the spins precess and try to return to their original state aligned with the Earth's magnetic field, they emit a microscopic signal (FID signal). The coil captures this, the amplifier circuit boosts it, and it is fed into the PC via a sound card.
  4. Analysis: The signal acquired in step 3 is processed using FFT and noise reduction in Python to observe the quantum state.

  System Configuration

  • Microcontroller: M5Stack
  • Sensor Coil: 250 meters of 0.5mm enamel wire, painstakingly hand-wound around a PVC pipe.
  • Proton Sample: Pure water
  • Polarization Circuit: Fully sealed Lead-Acid Battery (to prevent power supply noise), MOSFET, Fuses.
  • Amplifier Circuit: Ultra-low distortion/noise Op-Amps (AD797BRZ), Film Capacitors, Fast Recovery Diode.

  Development Logs: Past and Future

  I have been publishing my past development logs as a "Book" on Zenn (a Japanese tech blogging platform). However, I used AI to help write the text for those past logs because I actually started this project around April 2026, but only began writing articles in September 2026, so I had a lot...

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