Who’s afraid of Majorana qubits?


by Guanzhong Wang

Don’t hide it; don’t deny it. I know every time you, my dear friend in or related to the quantum computing community, hear about the words “topological qubits”, you raise your eyebrows slightly and say to yourself, “weird”… Pretend no more! We know you are puzzled why anyone would want to embark on the journey of making a topological qubit and how on earth they go about doing it. In this new series on topological qubits, we will try to explain to you why building such a seemingly unconventional qubit is rather fun and is even one of the natural choices when it comes to quantum computing.

I will start in this post with a virtual lab tour, hoping to give you an overview on where and how we look for the basic building blocks of a topological qubit—a Majorana bound state in condensed matter systems. From the particle that Ettore Majorana envisioned on a piece of paper to the nanowire devices and then back to the blueprints for a topological qubit, this will be a journey linking seemingly strange ideas to real, tangible chips in cryostats. If you’ve ever got curious about a Majorana qubit, gone through some reviews and tutorials but still wonder how experimentalists try to build them, this article is totally for you. If you haven’t, I hope it will arouse your interest in doing so! Continue reading Who’s afraid of Majorana qubits?

Happy Easter: looking for Quantum Eggs


It’s that time of the year again: the Easter Bunny comes by and hides his eggs. Everywhere you look he hid them: in the flower beds in the garden, underneath your bed, even if you open the cupboards, eggs come rolling out. Eggs in all kinds of clear colours and, if you’re lucky, made of chocolate.

But, over the past year, the Easter Bunny spent his time studying some quantum mechanics. He was inspired and decided to do something totally different this year. Instead of eggs, he hid some quantum terminology in the puzzle below. Can you find all the quantum eggs he hid?

Happy searching!

Can you find all the words?[1]

[1] This puzzle was made at WoordZoekerMaken.nl.
[2] The second ‘l’ in millikelvin got lost during the hiding…

Stitching Qubits


How to add qubits to an array one by one.

by Anne-Marije Zwerver

So it is winter and it is cold. Cold? It is freezing! But the air is nice and dry outside, so you decide to take a wintery walk in the forest. If you’re in a part of the world where you can currently fry an egg on the street, just wander along in your head – this is a small gedanken experiment. The walk is nice, yet cold and by the time you arrive home, the only thing you want, is to take a nice and warm shower. You turn on the tap and you feel the water running, splashing on your arms and shoulders, slowly defrosting your fingers. But then, for goodness sake, your roommate turns on her (cold) tap and your water temperature rises instantly. In a reflex, you jump out of the water jet, your skin already showing red stains. Luckily it was just an instant and soon you can go back into the shower. But then, of course, your other roommate needs some hot water and with a scream you, again, jump out of the now ice-cold shower. Time for a cup of tea…

Continue reading Stitching Qubits