Ultracold atoms in checkerboard pattern, symbolizing antiferromagnetic order.

Cooling Quantum Gases: Unlocking Secrets of Superconductivity

Beau Callahan in Science & Nature August 2025 • 4 min read.

"New research cools quantum gases to near absolute zero, offering unprecedented insights into exotic states of matter and high-temperature superconductivity."

In the realm of physics, the quest to understand the behavior of matter at its most fundamental level often leads scientists to explore extreme conditions. One such area of exploration involves cooling gases to temperatures near absolute zero, where quantum effects dominate. Recent research has achieved a significant breakthrough in this field, successfully cooling quantum gases to long-range antiferromagnetic order, a state where electron spins align in a repeating, opposite pattern.

This achievement marks a crucial step forward in the study of exotic states of matter and could pave the way for advancements in various technological applications, including quantum computing and materials science. The ability to control and manipulate matter at such low temperatures allows scientists to probe the intricate relationships between particles and gain insights into phenomena that are otherwise hidden at higher temperatures.

The driving force behind this research is the potential to unlock the secrets of high-temperature superconductivity. Superconductivity, the ability of a material to conduct electricity with no resistance, holds immense promise for energy-efficient technologies. However, the mechanisms behind high-temperature superconductivity remain largely mysterious. By studying quantum gases at extremely low temperatures, researchers hope to mimic the behavior of electrons in superconducting materials and gain a deeper understanding of the underlying physics.

The Significance of Antiferromagnetic Order

Ultracold atoms in checkerboard pattern, symbolizing antiferromagnetic order.

The observation of antiferromagnetic order in a lattice of ultracold atoms is a significant milestone. In this state, the spins of neighboring atoms align in opposite directions, creating a checkerboard pattern. This ordered arrangement arises from the interactions between the atoms, even though they are not directly touching. The ability to achieve and observe this state in a controlled environment provides a unique opportunity to study the fundamental principles of magnetism and quantum mechanics.

The connection between antiferromagnetism and high-temperature superconductivity lies in the idea that these two phenomena are closely related. In many high-temperature superconductors, the superconducting state emerges from a parent compound that exhibits antiferromagnetic order. By studying the transition from antiferromagnetism to superconductivity in ultracold atomic systems, researchers hope to gain insights into the mechanisms that drive high-temperature superconductivity.

Mimicking Superconductors: Cold-atom researchers are using neutral atoms in optical traps to mimic electrons in high-temperature superconductors.
Hubbard Model: The link between solid-state and cold-atom systems is the Hubbard model, describing electrons in solids.
Temperature Challenge: The primary hurdle is achieving low enough temperatures, as current atomic experiments are still far from cuprate phase diagrams.
Harvard's Breakthrough: Markus Greiner's team at Harvard achieved antiferromagnetic order by cooling lithium-6 atoms in an 80-site lattice.

Harvard University's Markus Greiner and his team have successfully cooled a system of lithium-6 atoms to the point where antiferromagnetic order is observed across the entire 80-site two-dimensional lattice. This achievement represents a significant step forward, as it allows scientists to probe the system with unprecedented precision and control. By manipulating the atoms in the lattice, researchers can study the interactions between them and gain insights into the factors that influence the formation of antiferromagnetic order.

The Future of Quantum Gas Research

The successful cooling of quantum gases to long-range antiferromagnetic order opens up a wide range of possibilities for future research. Scientists can now use these systems to study the fundamental properties of magnetism, explore the transition between different phases of matter, and potentially discover new materials with exotic properties. The insights gained from these studies could lead to advancements in various technological fields, including quantum computing, materials science, and energy technology.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1063/pt.3.3649, Alternate LINK

Title: Quantum Gases Cooled To Long-Range Antiferromagnetic Order

Subject: General Physics and Astronomy

Journal: Physics Today

Publisher: AIP Publishing

Authors: Johanna L. Miller

Published: 2017-08-01

Everything You Need To Know

Why is it important to cool quantum gases to temperatures near absolute zero?

Scientists cool quantum gases to near absolute zero to study exotic states of matter, particularly long-range antiferromagnetic order. This state, where electron spins align in a repeating, opposite pattern, provides insights into fundamental physics and the potential to unlock the secrets of high-temperature superconductivity. By achieving these low temperatures, researchers can observe and manipulate quantum phenomena that are otherwise hidden at higher temperatures.

What is 'antiferromagnetic order' and why is it significant in the context of studying quantum gases?

Antiferromagnetic order refers to a state where the spins of neighboring atoms align in opposite directions, creating a checkerboard pattern. Achieving this order in ultracold atomic systems allows scientists to study the fundamental principles of magnetism and quantum mechanics. The connection to high-temperature superconductivity is that many high-temperature superconductors emerge from parent compounds exhibiting antiferromagnetic order, offering a pathway to understanding superconductivity's mechanisms.

What is the Hubbard model, and how does it connect cold-atom systems to the study of high-temperature superconductors?

The Hubbard model serves as the theoretical bridge between solid-state systems and cold-atom systems. It describes the behavior of electrons in solids and provides a framework for understanding how interactions between electrons lead to complex phenomena like antiferromagnetism and superconductivity. Cold-atom researchers use neutral atoms in optical traps to mimic the behavior of electrons in high-temperature superconductors, using the Hubbard model to guide their experiments and interpret their results.

How did Markus Greiner's team at Harvard achieve antiferromagnetic order, and what specific system did they use?

Markus Greiner's team at Harvard University cooled lithium-6 atoms in an 80-site lattice to achieve antiferromagnetic order. This breakthrough involved trapping and cooling the atoms to extremely low temperatures where the spins of the atoms aligned in the characteristic checkerboard pattern. This allowed scientists to precisely probe the system and study the interactions that lead to antiferromagnetic order, providing valuable insights into the behavior of more complex materials.

What are the limitations in current experiments, specifically regarding temperature, and how does it affect the ability to fully understand high-temperature superconductivity?

While achieving antiferromagnetic order is a significant step, current atomic experiments are still far from reaching the temperatures needed to fully replicate the conditions in cuprate phase diagrams, which are crucial for understanding high-temperature superconductivity. Overcoming this temperature challenge involves developing new cooling techniques and experimental setups that can reach even lower temperatures, bringing the cold-atom systems closer to mimicking the behavior of real high-temperature superconductors and unlocking their secrets. The exploration of the transition between different phases of matter holds the potential to discover new materials with exotic properties.