Abstract
The problem of a quantum Ising degree of freedom coupled to a gapless bosonic mode appears naturally in many one-dimensional systems, yet surprisingly little is known how such a coupling affects the Ising quantum critical point. We investigate the fate of the critical point in a regime, where the weak coupling renormalization group (RG) indicates a flow toward strong coupling. Using a renormalization group analysis and numerical density matrix renormalization group (DMRG) calculations we show that, depending on the ratio of velocities of the gapless bosonic mode and the Ising critical fluctuations, the transition may remain continuous or become fluctuation-driven first order. The two regimes are separated by a tricritical point of a novel type.
| Original language | English |
|---|---|
| Article number | 075132 |
| Journal | Physical Review B |
| Volume | 95 |
| Issue number | 7 |
| DOIs | |
| State | Published - 17 Feb 2017 |
| Externally published | Yes |
Bibliographical note
Publisher Copyright:© 2017 American Physical Society.
Funding
We would like to thank Liza Huijse and Achim Rosch for useful discussions. E.A., J.R., and O.A. thank the ERC for financial support through the UQUAM synergy grant. J.R. acknowledges the support of fellowship from the Gordon and Betty Moore Foundation under the EPiQS initiative (Grant No. GBMF4303). E.B. acknowledges financial support from the European Research Council (ERC) under the European Unions Horizon 2020 research and innovation programme (Grant Agreement No. 639172), and under a Marie Curie CIG grant.
| Funders | Funder number |
|---|---|
| Gordon and Betty Moore Foundation | GBMF4303 |
| Horizon 2020 Framework Programme | |
| Marie Curie | |
| European Commission | |
| Horizon 2020 | 639172 |