Coherent Charge and Spin Density Waves in Underdoped HgBa$_{2}$CuO$_{4+\delta}$

TL;DR

This study reveals a coherent, temperature- and field-independent spin and charge density wave in the simple cuprate HgBa$_{2}$CuO$_{4+eta}$, highlighting variability in electronic instabilities among cuprates.

Contribution

It demonstrates the presence of a universal-like spin and charge order in Hg1201, contrasting with other cuprates where such order is field- or temperature-dependent.

Findings

Coherent spin and charge modulations are observed in Hg1201.

No evidence of field- or temperature-induced charge order in Hg1201.

Electronic instabilities vary across different cuprate materials.

Abstract

Various forms of spin and charge ordering have been identified in a wide range of cuprate superconducting materials, but whether these behaviors are ubiquitous phenomena is not established. In this work we focus on one of the simplest compounds, HgBa$_{2}$CuO$_{4+\delta}$ (Hg1201), a superconductor with a high transition temperature, 97 K, having only a single layer and tetragonal structure, in contrast to one of the most extensively studied materials, YBa$_{2}$Cu$_{3}$O$_{6+y}$ (Y123). Using nuclear magnetic resonance we have discovered a coherent spatial modulation of both spin and charge that is temperature and magnetic field independent, in competition with superconductivity similar to other cuprates. However, there is no evidence for the magnetic field and temperature induced charge order observed in Y123. Electronic instabilities are a common feature of cuprates as in the present work on Hg1201, but their manifestations are not universal.