Partner: N.E. Hussey


Recent publications
1.Chudziński P., Berben M., Xu X., Wakeham N., Bernáth B., Duffy C., Hinlopen R., Hsu Y., Wiedmann S., Tinnemans P., Jin R., Greenblatt M., Hussey N., Emergent symmetry in a low-dimensional superconductor on the edge of Mottness, Science, ISSN: 0036-8075, DOI: 10.1126/science.abp8948, Vol.382, pp.792-796, 2023
Abstract:

Upon cooling, condensed-matter systems typically transition into states of lower symmetry. The converse—i.e., the emergence of higher symmetry at lower temperatures—is extremely rare. In this work, we show how an unusually isotropic magnetoresistance in the highly anisotropic, one-dimensional conductor Li0.9Mo6O17 and its temperature dependence can be interpreted as a renormalization group (RG) flow toward a so-called separatrix. This approach is equivalent to an emergent symmetry in the system. The existence of two distinct ground states, Mott insulator and superconductor, can then be traced back to two opposing RG trajectories. By establishing a direct link between quantum field theory and an experimentally measurable quantity, we uncover a path through which emergent symmetry might be identified in other candidate materials.

Affiliations:
Chudziński P.-IPPT PAN
Berben M.-other affiliation
Xu X.-other affiliation
Wakeham N.-other affiliation
Bernáth B.-other affiliation
Duffy C.-other affiliation
Hinlopen R.-other affiliation
Hsu Y.-other affiliation
Wiedmann S.-other affiliation
Tinnemans P.-other affiliation
Jin R.-other affiliation
Greenblatt M.-other affiliation
Hussey N.-other affiliation
2.Lu J., Xu X., Greenblatt M., Jin R., Tinnemans P., Licciardello S., van Delft M.R., Buhot J., Chudziński P., Hussey N.E., Emergence of a real-space symmetry axis in the magnetoresistance of the one-dimensional conductor Li0.9Mo6O17, Science Advances, ISSN: 2375-2548, DOI: 10.1126/sciadv.aar8027, Vol.5, No.7, pp.eaar8027-1-7, 2019
Abstract:

We report on an emerging symmetry axis in the magnetoresistance of bulk single crystals of quasi–one-dimensional Li0.9Mo6O17 below Tmin = 25 K, the temperature at which the electrical resistivity experiences a minimum. Detailed angle-dependent magnetoresistance sweeps reveal that this symmetry axis is induced by the development of a negative magnetoresistance, which is suppressed only for magnetic fields oriented along the poles of the MoO6 octahedra that form the conducting chains. We show that this unusual negative magnetoresistance is consistent with the melting of dark excitons, composed of previously omitted orbitals within the t2g manifold that order below Tmin. The unveiled symmetry axis in directional magnetic fields not only provides evidence for the crystallization of these dark excitons but also sheds new light on the long-standing mystery of the metal-insulator transition in Li0.9Mo6O17.

Affiliations:
Lu J.-other affiliation
Xu X.-other affiliation
Greenblatt M.-other affiliation
Jin R.-other affiliation
Tinnemans P.-other affiliation
Licciardello S.-other affiliation
van Delft M.R.-other affiliation
Buhot J.-other affiliation
Chudziński P.-other affiliation
Hussey N.E.-other affiliation