quantum computing

49 Articles

Schrodinger’s Cat Lives

June 10, 2019 by 31 Comments

If quantum physics always sounded a little squirrelly to you, take heart. Yale researchers have announced that they can do what quantum physics claimed to be impossible: they can determine the state a quantum system will collapse to before it happens. This contradicts Schrodinger’s famous hypothetical cat that is superimposed as 50% alive and 50% dead at the same time. The research appears in Nature.

Schrodinger argued that until you open the box, the cat is half alive and half dead in the same way that a qubit can be in 50% of one state or another. When you observe it, you force the system to one state. Researchers at Yale, however, have found a way to use microwaves to indirectly monitor qubits to determine their state prior to the system making a jump. Unlike a normal observation which occurs too late, the Yale technique allows researchers to change the future state to their choice.

Continue reading “Schrodinger’s Cat Lives” →

Quantum Computing With QISKit

April 2, 2019 by 3 Comments

We all know that quantum computing is coming, but it is hard to know how to get started with it. [Mtreinish] suggests Qiskit — an Apache Licensed SDK for developing quantum applications. He has a presentation he gave in Singapore that you can see below, and a notebook you can go through on GitHub. If you are impatient, you can even run the notebook online through Google.

The tools can work against several backends including a simulator or the real hardware available from IBM. The official site has a different notebook you can use as a tutorial. Interestingly, the foundation of all Qiskit programs is “Terra” (the Earth) and permeating all Qiskit elements is Aer or air. There are also fire and water elements. At the bottom of the official notebook, you’ll find a lot of community notebooks that go deeper into specific topics.

Continue reading “Quantum Computing With QISKit” →

Door Springs And Neopixels Demonstrate Quantum Computing Principles

March 6, 2019 by 7 Comments

They may be out of style now, and something of a choking hazard for toddlers, but there’s no denying that spring doorstops make a great sound when they’re “plucked” by a foot as you walk by. Sure, maybe not on a 2:00 AM bathroom break when the rest of the house is sleeping, but certainly when used as sensors in this interactive light show.

The idea behind [Robin Baumgarten]’s “Quantum Garden” is clear from the first video below: engaging people through touch, sound, and light. Each of the 228 springs, surrounded by a Neopixel ring, is connected to one of the 12 inputs on an MPR121 capacitive touch sensor. The touch sensors and an accelerometer in the base detect which spring is sproinging and send that information to a pair of Teensies. A PC then runs the simulations that determine how the lights will react. The display is actually capable of some pretty complex responses, including full-on games. But the most interesting modes demonstrate principles of quantum computing, specifically stimulated Raman adiabatic passage (STIRAP), which describes transfers between quantum states. While the kids in the first video were a great stress test, the second video shows the display under less stimulation and gives a better idea of how it works.

We like this because it uses a simple mechanism of springs to demonstrate difficult quantum concepts in an engaging way. If you need more background on quantum computing, [Al Williams] has been covering the field for a while. Need the basics? Check out [Will Sweatman]’s primer.

Continue reading “Door Springs And Neopixels Demonstrate Quantum Computing Principles” →

Quantum Computing For Computer Scientists

July 13, 2018 by 16 Comments

Quantum computing is coming, so a lot of people are trying to articulate why we want it and how it works. Most of the explanations are either hardcore physics talking about spin and entanglement, or very breezy and handwaving which can be useful to get a little understanding but isn’t useful for applying the technology. Microsoft Research has a video that attempts to hit that spot in the middle — practical information for people who currently work with traditional computers. You can see the video below.

The video starts with basics you’d get from most videos talking about vector representation and operations. You have to get through about 17 minutes of that sort of thing until you get into qubits. If you glaze over on math, listen to the “index array” explanations [Andrew] gives after the math and you’ll be happier.

Continue reading “Quantum Computing For Computer Scientists” →

Flawed Synthetic Diamonds May Be Key For Quantum Computing

July 10, 2018 by 8 Comments

If you’ve followed any of our coverage of quantum computing, you probably know that the biggest challenge is getting quantum states to last very long, especially when moving them around. Researchers at Princeton may have solved this problem as they demonstrate storing qubits in a lab-created diamond. The actual publication is behind a paywall if you want to learn even more.

Generally, qubits are handled as photons and moved in optical fibers. However, they don’t last long in that state and it is difficult to store photons with correct quantum information. The impurities in diamonds though may have the ability to transfer a photon to an electron and back.

Continue reading “Flawed Synthetic Diamonds May Be Key For Quantum Computing” →

Wired And IBM Explain Quantum Computing To Students From Grade School To Grad School

June 26, 2018 by 10 Comments

Have you ever heard the old axiom that if you want to design a simple system, ask yourself if your grandmother could use it? Maybe that was on Wired’s mind because they asked a quantum computing expert — particularly IBM’s [Dr. Talia Gershon] — to explain what exactly quantum computing is at 5 levels. In the video they shot, which you can see below, [Dr. Gershon] talks to a younger child, a teenager, an undergraduate computer science student, a graduate student, and then a physicist.

We enjoyed some of the analogies of spinning pennies and the way she was able to bring the topic to an appropriate level for each of the participants. Truthfully, the final segment with the physicist ([Dr. Steven Girvin] was more of a conversation than an explanation, but it was interesting to hear his views on fault tolerance and how likely certain things were to occur in the near future.

Continue reading “Wired And IBM Explain Quantum Computing To Students From Grade School To Grad School” →

Simple Quantum Computing In 150 Lines Of Python

April 10, 2018 by 11 Comments

What does it take to build a quantum computer? Lots of exotic supercooled hardware. However, creating a simulator isn’t nearly as hard and can give you a lot of insight into how this kind of computing works. A simulator doesn’t even have to be complicated. Here’s one that exists in about 150 lines of Python code.

You might wonder what the value is. After all, there are plenty of well-done simulators including Quirk that we have looked at in the past. What’s charming about this simulator is that with only 150 lines of code, you can reasonably read the whole thing in a sitting and gain an understanding of how the different operations really affect the state.

Continue reading “Simple Quantum Computing In 150 Lines Of Python” →