Schrödinger’s cat video made with 2,024 atoms in quantum breakthrough

A team of physicists has created a video using just 2,024 rubidium atoms, showcasing a major advance in manipulating matter at the quantum level.

It has been described as “the world’s smallest cat video” that depicts the famous Schrödinger’s cat thought experiment. 

The quantum cat thought experiment, proposed by physicist Erwin Schrödinger in 1929, is a paradox designed to illustrate the bizarre concept of superposition, where a particle or object can exist in multiple states simultaneously. 

In the thought experiment, a cat in a sealed box is simultaneously dead and alive until the box is opened and its state is observed.

The new video brings this abstract idea to life, with atoms shifting to form images corresponding to the key moments of the experiment.

The researchers, from the University of Science and Technology of China, Shanghai, detailed this in a recent study.

Use of machine learning

In the video, each yellow dot represents a single rubidium atom moved within a 230-micron-wide array.

The atoms’ positions are tracked by detecting the light they give off, or fluoresce, when a laser moves them.

The video development depended on machine learning algorithms and optical tweezers.

Focused laser beams, or optical tweezers, work like “mini-tractor beams” to precisely move and arrange 2,024 rubidium atoms. The AI model performs real-time calculations to determine the best laser positions for moving all the atoms to their correct spots.

“We propose an AI-enabled, rapid, constant-time-overhead rearrangement protocol, and we experimentally assemble defect-free 2D and 3D atom arrays with up to 2024 atoms with a constant-time cost of 60 ms,” the researchers noted in the study paper. 

Using real-time calculations, the AI model creates holograms that direct a high-speed modulator to move all the atoms simultaneously.

Reportedly, this development overcomes a major bottleneck in neutral-atom quantum computing, where individual atoms were traditionally moved one by one, a time-consuming process that hindered scaling. 

The new method is incredibly fast, with the entire rearrangement taking a fraction of a second—just 60 milliseconds. 

To make the video viewable, the glowing atoms’ movement is slowed by a factor of 33. 

Advancing quantum computers

The South China Morning Post reported that the system demonstrated impressive accuracy, achieving 99.97% for single-qubit operations, 99.5% for two-qubit operations, and 99.92% for detecting the state of qubits.

The method is highly scalable because the time it takes to rearrange the atoms remains constant, even as the size of the array increases.

This technique goes beyond being a simple demonstration. Building the next generation of quantum computers depends on the ability to quickly and reliably assemble these arrays of atoms.

Compared to classical computers that use bits (0s and 1s), quantum computers use qubits, which can simultaneously be 0, 1, or both. These qubits, however, are extremely “fragile.”

“This protocol can be readily used to generate defect-free arrays of tens of thousands of atoms with current technologies and become a useful toolbox for quantum error correction,” the team wrote in the paper.

Quantum error correction is a key tool in quantum computing. and quantum computers can solve certain problems much more efficiently than classical computers.