A team of physicists at the University of Toronto (U of T) have taken a step toward making the essential building block of quantum computers out of pure light.
Their advance, described in a paper published this week in Nature Physics, has to do with a specific part of computer circuitry known as a “logic gate.”
Logic gates perform operations on input data to create new outputs. In classical computers, logic gates take the form of diodes or transistors. But quantum computer components are made from individual atoms and subatomic particles. Information processing happens when the particles interact with one another according to the strange laws of quantum physics.
Light particles – known as “photons” – have many advantages in quantum computing, but it is notoriously difficult to get them to interact with one another in useful ways. This experiment demonstrates how to create such interactions.
“We’ve seen the effect of a single particle of light on another optical beam,” said Canadian Institute for Advanced Research (CIFAR) Senior Fellow Aephraim Steinberg, one of the paper’s authors and a researcher at U of T’s Centre for Quantum Information & Quantum Computing. “Normally light beams pass through each other with no effect at all. To build technologies like optical quantum computers, you want your beams to talk to one another. That’s never been done before using a single photon.”
The interaction was a two-step process. The researchers shot a single photon at rubidium atoms that they had cooled to a millionth of a degree above absolute zero. The photons became “entangled” with the atoms, which affected the way the rubidium interacted with a separate optical beam. The photon changes the atoms’ refractive index, which caused a tiny but measurable “phase shift” in the beam.
This process could be used as an all-optical quantum logic gate, allowing for inputs, information-processing and outputs.
“Quantum logic gates are the most obvious application of this advance,” said Steinberg. “But being able to see these interactions is the starting page of an entirely new field of optics.
The Latest on: Quantum logic gates
via Google News
The Latest on: Quantum logic gates
- CNR in Milan develops super computer that beats Googleon August 16, 2021 at 6:07 pm
A team of researchers coordinated by Enrico Prati of the Institute for Photonics and Nanotechnologies (IFN) at the Italian National Research Council (CNR) in Milan developed a quantum computer that ...
- CNR in Milan develops super computer that beats Googleon August 16, 2021 at 1:08 pm
Applying artificial intelligence and deep learning to the compiler opened the way for programming an algorithm that adapts to any quantum computer based on logic gates. The result was obtained ...
- Everything You Wanted to Know about Quantum Computingon August 15, 2021 at 5:00 pm
At the moment, I have If, Then, Else, Boolean logic, and other things that I write for my program...I have to write that in quantum's language now. You need an interface to put that into the system ...
- Quantum Weirdness In Your Browseron August 13, 2021 at 4:59 pm
That’s not quantum weirdness, a NaN is a normal software bug. If you are accustomed to normal logic gates, you know that you don’t need all of them. For example, a NAND gate is sufficient to ...
- Implementation of a quantum conditional phase gate for the quantum fourier transform in circuit QEDon August 11, 2021 at 8:05 pm
It is well known that multiple superconducting charge qubits coupled to a transmission line resonator can be controlled to achieve quantum logic gates between two arbitrary qubits. We propose a scheme ...
- New theory hints at more efficient way to develop quantum algorithmson August 2, 2021 at 5:00 pm
Logic gates are the fundamental building blocks of digital computing systems. This is true for both conventional digital computers and future quantum computers; each processes information by ...
via Bing News