Fermionic criticality of anisotropic nodal point semimetals away from the upper critical dimension: Exact exponents to leading order in 
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Uryszek, Mikolaj D.; Krüger, Frank; Christou, Elliot

doi:10.1103/physrevresearch.2.043265

Cited by 8 publications

(12 citation statements)

References 83 publications

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“…These exponents are in agreement with those obtained from soft cutoff RG [41] and with previous results using the large N conformal bootstrap [49][50][51] and the critical point large N formalism [52][53][54]. At P clean , the order parameter mass m 2 is the only relevant parameter, representing the tuning parameter of the quantum phase transition.…”

Section: A Rg Flow and Fixed Pointssupporting

confidence: 90%

“…We have used the RPA fermion loop resummation to self-consistently account for the Landau damping of the boson dynamics by electronic particle-hole excitations. As pointed out in the literature [41,42], this is a non-perturbative effect in two spatial dimensions that changes the IR physics and hence the universal critical behavior. As we have demonstrated in our work, Landau damping also plays a crucial role in how the critical system responds to disorder.…”

Section: Discussionmentioning

confidence: 90%

“…Since the leading IR behavior of the integral for Π(k, ω) is independent of the UV momentum cut-off we can send the cut-off to infinity and perform the integration over the entire three dimensional frequency-momentum space. This leads to the result [41]…”

Section: B Landau Damping Of Order-parameter Fluctuations In D =mentioning

confidence: 91%

“…It renders the order parameter propagator non-analytic in the IR limit, thereby changing the universal critical behavior [41,42]. This physics is not captured by the expansion since the boson propagator remains analytic at the upper critical dimension.…”

Section: Introductionmentioning

confidence: 99%

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Interplay of interactions and disorder at the charge-density wave transition of two-dimensional Dirac semimetals

Uryszek,

Krüger

2021

Preprint

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Section: A Rg Flow and Fixed Pointssupporting

confidence: 90%

Section: Discussionmentioning

confidence: 90%

Section: B Landau Damping Of Order-parameter Fluctuations In D =mentioning

confidence: 91%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Interplay of interactions and disorder at the charge-density wave transition of two-dimensional Dirac semimetals

Uryszek,

Krüger

2021

Preprint

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“…Away from the upper critical dimension, the Landau damping of long-wavelength orderparameter fluctuations is a nonperturbative effect. It renders the order parameter propagator nonanalytic in the IR limit, thereby changing the universal critical behavior [42,43]. This physics is not captured by the expansion since the boson propagator remains analytic at the upper critical dimension.…”

Section: Introductionmentioning

confidence: 99%

Interplay of interactions and disorder at the charge density wave transition of two-dimensional Dirac semimetals

Uryszek

Krüger

2022

Phys. Rev. B

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We consider the effects of weak quenched fermionic disorder on the quantum-phase transition between the Dirac semimetal and charge density wave (CDW) insulator in two spatial dimensions. The symmetry breaking transition is described by the Gross-Neveu-Yukawa (GNY) theory of Dirac fermions coupled to an Ising order parameter field. Treating the disorder using the replica method, we consider chemical potential, vector potential (gauge), and random mass disorders, which all arise from nonmagnetic charged impurities. We self-consistently account for the Landau damping of long-wavelength order-parameter fluctuations by using the nonperturbative RPA resummation of fermion loops and compute the renormalization-group (RG) flow to leading order in the disorder strength and 1/N (N the number of Dirac fermion flavors). We find two fixed points, the clean GNY critical point, which is stable against weak disorder, and a dirty GNY multicritical point, at which the chemical potential disorder is finite and the other forms of disorder are irrelevant. We investigate the scaling of physical observables at this finite-disorder multicritical point which breaks Lorentz invariance and gives rise to distinct non-Fermi liquid behavior.

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Stability of the Néel quantum critical point in the presence of Dirac fermions

Lin²,

Uryszek³

et al. 2023

Phys. Rev. B

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We investigate the stability of the Néel quantum critical point of two-dimensional quantum antiferromagnets, described by a nonlinear σ model, in the presence of a Kondo coupling to N f flavors of two-component Dirac fermion fields. The long-wavelength order parameter fluctuations are subject to Landau damping by electronic particle-hole fluctuations. Using the momentum-shell renormalization group (RG), we demonstrate that the Landau damping is weakly irrelevant at the Néel quantum critical point, despite the fact that the corresponding self-energy correction dominates over the quadratic gradient terms in the IR limit. In the ordered phase, the Landau damping increases under the RG, indicative of damped spin-wave excitations. Although the Kondo coupling is weakly relevant, sufficiently strong Landau damping renders the Néel quantum critical point quasistable for N f 4 and thermodynamically stable for N f < 4. In the latter case, we identify a multicritical point which describes the transition between the Néel critical and Kondo runaway regimes. The symmetry breaking at this fixed point results in the opening of a gap in the Dirac fermion spectrum. Approaching the multicritical point from the disordered phase, the fermionic quasiparticle residue vanishes, giving rise to non-Fermi-liquid behavior.

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Fermionic criticality of anisotropic nodal point semimetals away from the upper critical dimension: Exact exponents to leading order in 1Nf

Cited by 8 publications

References 83 publications

Interplay of interactions and disorder at the charge-density wave transition of two-dimensional Dirac semimetals

Interplay of interactions and disorder at the charge-density wave transition of two-dimensional Dirac semimetals

Interplay of interactions and disorder at the charge density wave transition of two-dimensional Dirac semimetals

Stability of the Néel quantum critical point in the presence of Dirac fermions

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