Anatomy of a two-qubit quantum desktop computer
This nifty-looking "quantum computer" is a new concept that claims to teach you the basic building blocks of quantum computation. It is certainly more than just a toy. But, does it even compare to Google's device or IBM's 432 qubit system? The answer is no. The two cannot be compared. Larger scale hardware serves different purposes, this box designed for education purposes. With a price tag close to that of a used Ford Explorer, this little guy provides a unique opportunity to learn the fundamentals of gate and circuit building, or the basics of programming circuits or running algorithms. If you wanted one for yourself, it would cost between $5 and $6,000. A much higher price tag is attached to the "upgraded" model.
Today's post is about SpinQ's entry level desktop quantum computer. I'll cover the other two models and break down the included application interface in my next post.
Although this device is small and has only two qubits, it claims that experimenting with its interface, running preset algorithms, and examining included applications will allow you to learn a great deal. Sounds good? As an appetizer, it's like dipping into a sauce to get you excited for the main course.
The product's name is Gemini, a two-qubits desktop NMR quantum computer. Based on what i have found online, since its founding in 2018, SpinQ provides one-stop solutions in quantum computing based on their knowledge and experience in quantum development. This company also offers cloud solutions and a Superconducting quantum computer which uses superconducting circuits with Josephson junction for quantum computing. In future posts, I will discuss that device. Our understanding of this product will be enhanced if we delve into the quantum methodology used as the calculation engine.
One of several proposed approaches for constructing a quantum computer is NMR. It uses the spin states of nuclei within molecules as qubits. It is obvious that this method is less scalable and not a prime choice for developing ground-breaking scaled quantum solutions. As an educational tool, it is hailed as excellent by the company although I am looking for some reviews from users. To play with one of these units, I would have to stay awake many nights in a row. It reminds me of my first RadioShack PC IBM clone with 64k memory and floppy disk drive. Around 1982, I believe.
Back to Gemini product, according to the product design press releases it is possible to implement the system as a variation of nuclear magnetic resonance spectroscopy by probing quantum states through nuclear magnetic resonances. So, it may offer other uses. One thing to note that unlike other quantum computer implementations such as Ion Trapping, or Cold Atom, the NMR method uses "ensembles of systems," in this case "molecules," rather than a "single pure state." The word "ensemble" refers to a group of items viewed as a whole rather than individually.
Initially, in previous years, liquid state NMR (LSNMR) used the spin properties of atoms of particular molecules as qubits. Currently, solid state NMR (SSNMR) is the preferred method of quantum computation solid state NMR (SSNMR) as a means of quantum computation.
An old concept, a new design -
So we are looking at a desktop quantum computer with two qubits based on a technology that dates back to the 1970s when quantum computation was envisioned using nature. How does it work?
At the core of the system RF pulses are used to read and operate qubit states by utilizing nuclear magnetic resonance's spin phenomenon. That's the primary engine calculation concept behind the device. There are some simple scientific experiments you can do with Gemini that can help you learn about quantum computing. The desktop system comes with examples of running different algorithms, including Deutsch, Grover, and HHL algorithms.
It would be interesting to see if I could calculate a problem that classical computers couldn't. In the case of only two qubits, I am not sure. But instead I can learn how to gate two of them and run a circuit and learn to design one and much more. That is like doing baby steps of quantum computing. I remember, my Radio Shack clone allowed me to play a few games, type a letter, and run a small spreadsheet. In those days, it was pretty cool!
The hardware -
So this hardware, the Gemini Mini desktop quantum pc is the company's entry-level system, a 200 x 350 x 260mm, 14 kg device (about 30-pounds) with a two-qubit solution (hence the name) and a coherence time of >20 ms. Apparently, this coherence limit gives us enough time to run some programs before the data is destroyed by decoherence.
According to the online literature, on a single qubit, the Gemini Mini can perform over thirty gate operations, and on a two-qubit circuit, more than ten. A screen is integrated into the unit, along with documentation and training materials for 18 demo algorithms. The power consumption is 60 W (including the screen). And that means it run in room temperature. It costs about USD5-6k.
Now lets look at the NMR system and this desktop device a bit closer.
Nuclear magnetic resonance manipulates the spins of atoms by trapping them inside a magnetic field and zapping them with radio frequency pulses. In response to the radio pulses, the relaxed atoms emit radio frequency signals and exhibit their new state. During this new state, the spin of atoms can be interchanged (0 into 1) and interact with the spins of atoms nearby. Mathematical operations (quantum gates) can be induced by this interaction and the results can be recorded.
Is nature at work?
Yes. Molecular Dimethyphosphite serves as the central component of the SpinQ machine. A Hydrogen atom, a Phosphorus atom, an Oxygen atom, and two CH3O groups make up this molecule (Tetrahedral molecule). A "tetrahedral's phosphorus and hydrogen atoms" are close enough to interact and be manipulated separately, making it a suitable compound to manipulate. "Dimethylphosphite" is colorless and liquid at room temperature and that is useful to the SpinQ concept. Molecules are used to make sure the radio signals from the atoms are strong enough to be read by placing a small drop of liquid in the middle of the magnetic field. In the early days of quantum computing, this process was used to build quantum computers.
The software -
Here are the features I read in the published data, and below is a brief summary.
Spectroscopy parameters like temperature and field shimming can be calibrated with instrument calibration.
You can get the nuclear magnetic resonance signal with NMR spectroscopy.
Interface for the quantum computing module.
Task management and dynamic library modules support cloud computing and APIs, respectively.
The list goes on:
Dimethylphosphite Molecules: Dimethylphosphite's 31P and 1H nuclear spins connect directly to form the SpinQ's two-qubit processor.
FPGA, analog-digital converter, ADC, digital-analog converter DAC, and other digital parts are on the master board, inside the box. The algorithm that generates RF pulses and measures readout signals is in these parts. FPGA is field-programmable gate array (FPGA).
Magnets: They make a homogeneous magnetic field for splitting nuclei and creating qubits.
RF Pulse Generation System: Since the nuclei's Lamor frequency is within the range of RF pulses, the RF pulse generation system maintains the quantum state. Larmor frequencies range from 43 to 170 MHz.43 to 170 MHz The frequencies in this range are radio frequency (RF), which is lower than X-rays and does not disrupt living tissues. If you are going to bring this thing into your kitchen table, you should consider this.
Field Shimming: You get less than 1ppm "homogeneity" when you shift from 20ppm to 1ppm. It means, physics-wise, that homogeneous materials or systems have the same properties at all points; they are uniform. A uniform electric field (which is the same strength and direction at all points) would be consistent with homogeneity (all points experience the same physics).
It's a magnetic field at room temperature. A temperature control module ensures permanent magnets do not exceed room temperature.
The upgraded model will be covered in the next post.
White phosphorus, yellow phosphorus or simply tetraphosphorus (P 4) exists as molecules made up of four atoms in a tetrahedral structure. The tetrahedral arrangement results in ring strain and instability. The molecule is described as consisting of six single P–P bonds. Two crystalline forms are known.
Dimethyl hydrogen phosphite, also known as Dimethylphosphite, is an organophosphorus compound with the formula (CH₃O)₂PH. It is a reagent for generating other organophosphorus compounds, exploiting the high reactivity of the P-H bond. The molecule is tetrahedral. It is a colorless liquid.
What is shimming and why is it needed?
Even following the most rigorous manufacturing tolerances, the homogeneity of an MR magnet arriving fresh from the factory will likely be two orders of magnitude away from ideal specifications levels. Once the magnet is sited in the imaging suite, its field will be further distorted by the presence of metal in pipes, wires, ducts, and structural beams in the immediate environment. Fringe fields of nearby scanners may also affect the field of the newly installed magnet. Shimming is the process by which the main magnetic field (Bo) is made more homogenous.
Shimming may be passive, active, or both. In passive shimming small pieces of sheet metal or ferromagnetic pellets are affixed at various locations within the scanner bore. In active shimming, currents are directed through specialized coils to further improve homogeneity. Each of these shimming techniques will be described in detail in the next two questions.
https://mriquestions.com/why-shimming.html