# Ground state selection under pressure in the quantum pyrochlore magnet Yb2Ti2O7

## TL;DR

This study reveals that applying pressure to Yb2Ti2O7 induces a transition from a disordered, non-magnetic state to a splayed ferromagnetic state, clarifying its low-temperature magnetic behavior.

## Contribution

The paper demonstrates that pressure sensitivity explains the low-temperature magnetic properties of Yb2Ti2O7, a quantum spin ice candidate, through combined neutron diffraction and muon spin relaxation experiments.

## Key findings

- Pressure induces a magnetic transition in Yb2Ti2O7.
- Disordered non-magnetic ground state transforms into splayed ferromagnetic state.
- Provides insight into the low-temperature behavior of quantum spin ice materials.

## Abstract

A quantum spin liquid is a novel state of matter characterized by quantum entanglement and the absence of any broken symmetry. In condensed matter, the frustrated rare-earth pyrochlore magnets Ho$_2$Ti$_2$O$_7$ and Dy$_2$Ti$_2$O$_7$, so-called spin ices, exhibit a classical spin liquid state with fractionalized thermal excitations (magnetic monopoles). Evidence for a quantum spin ice, in which the magnetic monopoles become long range entangled and an emergent quantum electrodynamics arises, seems within reach. The magnetic properties of the quantum spin ice candidate Yb$_2$Ti$_2$O$_7$ have eluded a global understanding and even the presence or absence of static magnetic order at low temperatures is controversial. Here we show that sensitivity to pressure is the missing key to the low temperature behaviour of Yb$_2$Ti$_2$O$_7$. By combining neutron diffraction and muon spin relaxation on a stoichiometric sample under pressure, we evidence a magnetic transition from a disordered, non-magnetic, ground state to a splayed ferromagnetic ground state.