Quantum spin chains undergoing phase transition.

Unlocking Quantum Secrets: How Spin Squeezing Could Revolutionize Material Science

Avery Sinclair in Science & Nature December 2025 • 4 min read.

"New research leverages quantum renormalization to explore phase transitions, offering insights into material behavior at the quantum level and paving the way for advanced material design."

Quantum phase transitions (QPTs) have captivated the scientific community, marking a pivotal shift in how we perceive matter at its most fundamental level. Unlike classical phase transitions that rely on temperature, QPTs are triggered by altering parameters such as magnetic field or pressure near absolute zero. This unveils drastic changes in a material's ground state properties at a quantum critical point (QCP).

Pinpointing these QCPs is crucial for understanding and harnessing the unique behaviors of strongly correlated systems, which are essential in developing advanced materials and technologies. The quantum realm's inherent fluctuations, which dominate at these low temperatures, have inspired researchers to apply quantum information theory to detect and analyze QPTs, offering new perspectives on material science.

The quantum renormalization group (QRG) method, pioneered by Wilson in 1975, has emerged as a powerful tool for investigating the intricacies of quantum correlations within many-body systems. By iteratively simplifying the system while preserving its essential physics, QRG allows scientists to study phenomena like entanglement, quantum discord, and fidelity near QCPs. Recent research has introduced 'spin squeezing' as a novel indicator of QPTs, providing new insights into the quantum properties of spin chains.

What is Spin Squeezing and How Does it Reveal Quantum Secrets?

Quantum spin chains undergoing phase transition.

Spin squeezing is a quantum phenomenon where the uncertainty in one spin component is reduced at the expense of increased uncertainty in another. This 'squeezing' provides a sensitive measure of quantum correlations between spins, making it an effective tool for detecting multipartite entanglement in many-spin systems. Its experimental accessibility and potential to enhance measurement precision have garnered significant attention.

Researchers have successfully applied the QRG method to investigate quantum phase transitions in various spin models, including the Ising transverse field (ITF) model and the XXZ Heisenberg model, both with and without the Dzyaloshinskii-Moriya (DM) interaction. By analyzing the spin squeezing parameter after each QRG step, they observed abrupt changes at the quantum critical point (QCP), signaling a QPT.

Here's what this research reveals:

QPT Detection: Spin squeezing accurately identifies quantum phase transitions in spin models.
Discontinuous Behavior: The derivative of the spin squeezing parameter shows a clear discontinuity at the QCP.
Critical Exponents: Spin squeezing connects to the critical exponent of the correlation length.

This method involves calculating a spin squeezing parameter through analytical expressions at each step of QRG. As the system's scale increases through these iterative steps, the ground state spin squeezing parameters exhibit a sharp change at the QCP. Notably, in all studied models, the first derivative of the spin squeezing parameter shows a discontinuity with respect to the control parameter, confirming its utility as a QPT indicator. Furthermore, the spin squeezing parameters converge to saturated values after sufficient QRG iterations, and the divergence exponent near the QCP links directly to the critical exponent of the correlation length.

The Future of Material Design: Quantum Insights Leading the Way

This research demonstrates the potential of spin squeezing as a QPT indicator, which can be used to explore and characterize quantum materials. By applying the QRG procedure, scientists are uncovering new ways to study quantum information properties in complex systems, potentially leading to the design of novel materials with unprecedented functionalities. This approach not only enhances our theoretical understanding but also paves the way for practical applications in quantum computing and advanced material technologies.

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: 10.1038/s41598-018-35666-z, Alternate LINK

Title: Quantum Renormalization Of Spin Squeezing In Spin Chains

Subject: Multidisciplinary

Journal: Scientific Reports

Publisher: Springer Science and Business Media LLC

Authors: Leila Balazadeh, Ghader Najarbashi, Ali Tavana

Published: 2018-12-01

Everything You Need To Know

What is spin squeezing, and why is it important for understanding materials?

Spin squeezing is a quantum phenomenon where the uncertainty in one spin component is reduced, while the uncertainty in another is increased. This 'squeezing' provides a sensitive measure of quantum correlations, effectively detecting multipartite entanglement in many-spin systems. This is significant because it acts as a sensitive indicator for Quantum Phase Transitions (QPTs). It allows scientists to pinpoint Quantum Critical Points (QCPs), which are crucial for understanding and harnessing the unique behaviors of strongly correlated systems, essential for advanced material design.

What are Quantum Phase Transitions (QPTs), and why are they significant in material science?

Quantum Phase Transitions (QPTs) are phase transitions triggered by altering parameters such as magnetic field or pressure near absolute zero. Unlike classical phase transitions driven by temperature, QPTs reveal drastic changes in a material's ground state properties at a Quantum Critical Point (QCP). The significance of QPTs lies in their ability to reveal the fundamental behaviors of matter at its most fundamental level, driving a shift in our understanding of material properties. Understanding and controlling QPTs is crucial for the development of advanced materials with novel functionalities.

How does the Quantum Renormalization Group (QRG) method help in understanding quantum materials?

The Quantum Renormalization Group (QRG) method, pioneered by Wilson, is a powerful tool for investigating quantum correlations within many-body systems. The QRG method simplifies the system iteratively while preserving its essential physics. This allows scientists to study phenomena like entanglement and fidelity near Quantum Critical Points (QCPs). In this context, QRG is used with spin squeezing to study quantum phase transitions in various spin models. Analyzing the spin squeezing parameter after each QRG step reveals changes at the QCP, signaling a QPT, and linking directly to the critical exponent of the correlation length.

What is a Quantum Critical Point (QCP), and why is it essential to material research?

The Quantum Critical Point (QCP) is a specific point where a Quantum Phase Transition (QPT) occurs. It's the point where a material's ground state properties undergo drastic changes. Pinpointing these QCPs is crucial because it allows for a deeper understanding of the unique behaviors of strongly correlated systems. Scientists use spin squeezing and the Quantum Renormalization Group (QRG) method to accurately identify these points and uncover new insights into material behavior.

What are the Ising transverse field (ITF) model and the XXZ Heisenberg model, and how are they used in this research?

The Ising transverse field (ITF) model and the XXZ Heisenberg model are specific spin models used to study quantum phase transitions using spin squeezing and the Quantum Renormalization Group (QRG) method. Both models are studied with and without the Dzyaloshinskii-Moriya (DM) interaction. These models are chosen to test and validate the spin squeezing method because they represent different scenarios where QPTs occur. By analyzing the spin squeezing parameter within these models, researchers can identify the Quantum Critical Points (QCPs) and gain insights into the quantum properties of spin chains.