Related papers: Emerging quantum critical phase in a cluster spin-…
Understanding how frustration and disorder shape relaxation in complex systems is a central problem in statistical physics and quantum annealing. Spin-glass models provide a natural framework to explore this connection, as their energy…
Highly frustrated systems have macroscopically degenerate ground states that lead to novel properties. In magnetism its consequences underpin exotic and technologically important effects, such as, high temperature superconductivity,…
Studies on the heavy-fermion pyrochlore iridate (Pr$_2$Ir$_2$O$_7$) point to the role of time-reversal-symmetry breaking in geometrically frustrated Kondo lattices. With this motivation, here we study the effect of Kondo coupling and chiral…
A growing body of evidence suggests that the quantum critical behavior at the onset of magnetism in heavy fermion systems can not be understood in terms of a simple quantum spin density wave. This talk will discuss the consequences of this…
Ising spin glasses in a transverse field exhibit a zero temperature quantum phase transition, which is driven by quantum rather than thermal fluctuations. They constitute a universality class that is significantly different from the…
We report a comprehensive study of CeIn$_{3-x}$Sn$_x$ $(0.55 \leq x \leq 0.8)$ single crystals close to the antiferromagnetic (AF) quantum critical point (QCP) at $x_c\approx 0.67$ by means of the low-temperature thermal expansion and…
The appearance of unconventional superconductivity near heavy-fermion quantum critical points (QCPs) motivates investigation of pairing correlations close to a ``beyond Landau'' Kondo-destruction QCP. We focus on a two-Anderson-impurity…
The zero-temperature limit of a continuous phase transition is marked by a quantum critical point, which can generate exotic physics that extends to elevated temperatures. Magnetic quantum criticality is now well known, and has been…
The standard description of quantum critical points takes into account only fluctuations of the order parameter, and treats quantum fluctuations as extra dimensions of classical fluctuations. This picture can break down in a qualitative…
We propose a general theoretical framework, using two layers of ancilla qubits, for deconfined criticality between a Fermi liquid with a large Fermi surface, and a pseudogap metal with a small Fermi surface of electron-like quasiparticles.…
Here, we unveil evidence for a quantum phase-transition in CeCu_2Ge_2 which displays both an incommensurate spin-density wave (SDW) ground-state, and a strong renormalization of the quasiparticle effective masses (mu) due to the…
Magnetic impurities in neutral graphene provide a realization of the pseudogap Kondo model, which displays a quantum phase transition between phases with screened and unscreened impurity moment. Here, we present a detailed study of the…
Strange metals defy the quasiparticle description of conventional metals, exhibiting a linear in temperature ($T$-linear) resistivity in a broad temperature range. It has become increasingly clear that, together with $T$-linear resistivity,…
Spin-glass magnetism confined to individual weakly interacting vortices is detected in two different families of high-transition-temperature (T_c) superconductors, but only in samples on the low-doping side of the low-temperature normal…
We consider quantum critical points (QCP) in which quantum fluctuations associated with charge rather than magnetic order induce unconventional metallic properties. Based on finite-T calculations on a two-dimensional extended Hubbard model…
Physics of quantum critical point is one of the most perplexing topics in current condensed-matter physics. Its conclusive understanding is forestalled by the scarcity of experimental systems displaying novel aspects of quantum criticality.…
We review recent work on the instability of the heavy Fermi liquid state (FL) of the Kondo lattice towards a magnetic metal in which the local moments are not part of the Fermi sea. Using insights drawn from the theory of deconfined quantum…
Quantum criticality in certain heavy-fermion metals is believed to go beyond the Landau framework of order-parameter fluctuations. In particular, there is considerable evidence for Kondo destruction: a disappearance of the static Kondo…
Quantum fluctuations originating phase competition or geometrical frustration of spins lead to novel states such as a quantum critical point and a quantum spin liquid where the strong quantum fluctuations suppress any ordered states even at…
SmB6 is a promising candidate material that promises to elucidate the connection between strong correlations and topological electronic states, which is a major challenge in condensed matter physics. The electron correlations are…