Research using a quantum computer as a physical platform for quantum experiments has found a way to custom-design and mark magnetic objects using quantum bits, or qubits. This opens up a new approach for developing new materials and powerful quantum computing.
“With the help of quantum annealing, we have demonstrated a new method for modeling magnetic states,” said Alejandro López-Pizzanella, a hypothetical experimentalist in the theoretical department at Los Alamos National Laboratory. Lopez-Bezanilla is the corresponding author of a research paper on research in Science advances.
“We have shown that a quasi-crystalline magnetic lattice can host states beyond the zero and one-bit states of classical IT,” said López-Pizzanella. “By applying a magnetic field to a finite set of spins, we can transform the magnetic landscape of a quasicrystal object.”
“A quasi-crystal is a structure that consists of repeating some basic shapes that follow different rules than those found in ordinary crystals,” he said.
For this work with Cristiano Nisoli, a theoretical physicist also at Los Alamos, the D-Wave quantum annealing computer served as a platform for doing actual physics experiments on quasicrystals, rather than modeling them. This approach, Lopez-Bezanilla said, “allows matter to speak to you, because instead of running computer code, we go straight into the quantum platform and tune all physical interactions at will.”
The rise and fall of qubits
Lopez-Bezanilla selected 201 qubits on a D-Wave computer and linked them together to reproduce the shape of a Penrose quasicrystal.
Since Roger Penrose conceived of the non-periodic structures named after him in the 1970s, no one has rotated each of his nodes to observe their behavior under the influence of a magnetic field.
“I linked the qubits, so they all reproduce the geometry of one of his quasicrystals, the so-called P3,” said Lopez-Bezanilla. “To my surprise, I noticed that applying specific external magnetic fields to the structure caused some qubits to show up and down directions with the same probability, which leads the P3 quasicrystal to adopt a rich variety of magnetic shapes.”
Manipulating the interaction strength of qubits and qubits with the external field causes the quasiprystals to settle into different magnetic arrangements, making it possible to encode more than one bit of information into a single object.
Some of these configurations do not show any exact order of the direction of the qubits.
“This could play to our advantage, because they could potentially host quantum quasiparticles important for information science,” Lopez-Pizzanella said. The spin quasiparticle is able to carry information that is immune to external noise.
A quasiparticle is a convenient way to describe the collective behavior of a group of fundamental elements. Properties such as mass and charge can be attributed to multiple rolls that move as if they were one.
