SU(2)-Symmetric Spin-Boson Model: Quantum Criticality, Fixed-Point Annihilation, and Duality
Research output: Contribution to journal › Research article › Contributed › peer-review
Contributors
Abstract
The annihilation of two intermediate-coupling renormalization-group (RG) fixed points is of interest in diverse fields from statistical mechanics to high-energy physics, but has so far only been studied using perturbative techniques. Here we present high-accuracy quantum Monte Carlo results for the SU(2)-symmetric S=1/2 spin-boson (or Bose-Kondo) model. We study the model with a power-law bath spectrum ∝ωs where, in addition to a critical phase predicted by perturbative RG, a stable strong-coupling phase is present. Using a detailed scaling analysis, we provide direct numerical evidence for the collision and annihilation of two RG fixed points at s∗=0.6540(2), causing the critical phase to disappear for s<s∗. In particular, we uncover a surprising duality between the two fixed points, corresponding to a reflection symmetry of the RG beta function, which we utilize to make analytical predictions at strong coupling which are in excellent agreement with numerics. Our work makes phenomena of fixed-point annihilation accessible to large-scale simulations, and we comment on the consequences for impurity moments in critical magnets.
Details
Original language | English |
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Article number | 186701 |
Number of pages | 6 |
Journal | Phys. Rev. Lett. |
Volume | 130(2023) |
Issue number | 18 |
Publication status | Published - 1 May 2023 |
Peer-reviewed | Yes |
External IDs
Scopus | 85158825450 |
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WOS | 000986445800004 |
Keywords
Research priority areas of TU Dresden
ASJC Scopus subject areas
Keywords
- Phase-transitions, Impurity, 1st-order, Dynamics