相关论文: Field-tuned quantum critical point of antiferromag…
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 discuss the interplay between anti-ferromagnetic order and polarization fluctuations in a magnetic quantum paraelectric. Using an action where anti-ferromagnetic order parameter couples to the polarization fluctuations and as well as…
We study the temperature-dependent quantum correction to conductivity due to the interplay of spin density fluctuations and weak disorder for a two-dimensional metal near an antiferromagnetic (AFM) quantum critical point. AFM spin density…
The interpretation of the magnetic phase diagrams of strongly correlated electron systems remains controversial. In particular, the physics of quantum phase transitions, which occur at zero temperature, is still enigmatic. Heavy-fermion…
We investigate the role of disorder for field-driven quantum phase transitions of metallic antiferromagnets. For systems with sufficiently low symmetry, the combination of a uniform external field and non-magnetic impurities leads…
There are two views of antiferromagnets. The first proceeds from atomic physics, which predicts that atoms with unpaired electrons develop magnetic moments. In a solid, the coupling between moments on nearby ions then yields…
In low-temperature metallic magnets, ferromagnetic (FM) and antiferromagnetic (AFM) orders can exist in a single system in different parts of the phase diagram as a function of some control parameter. These phases can be adjacent, or exist…
Quantum phase transitions have captured the interest of a large community in condensed-matter and atom physics research. The common feature of these very different material classes lies in the fact that the competition between low-energy…
We report spontaneous appearance of antiferromagnetic order in a model gapped quantum paramagnet Ni(Cl$_{1-x}$Br$_x$)$_2$$\cdot$4SC(NH$_2$)$_2$ induced by a change in bromine concentration x. This transition is qualitatively similar to a z…
Critical thermodynamics close to a metamagnetic quantum critical endpoint (QCEP) in a metal is discussed within the framework of spin-fluctuation theory. We analyze the effective potential for the Ising order parameter that is renormalized…
We investigate the quantum phase transition of itinerant ferromagnets. It is shown that correlation effects in the underlying itinerant electron system lead to singularities in the order parameter field theory that result in an effective…
Using the spin wave approximation, we study the decoherence dynamics of a central spin coupled to an antiferromagnetic environment under the application of an external global magnetic field. The external magnetic field affects the…
We propose a phenomenological spin fluctuation theory for antiferromagnetic quantum tricritical point (QTCP), where the first-order phase transition changes into the continuous one at zero temperature. Under magnetic fields, ferromagnetic…
We investigate the interplay of quantum fluctuations and magnetic anisotropies in metallic ferromagnets. Our central result is that fluctuations close to a quantum critical point can drive the moments to point along a magnetic hard axis. As…
Strongly correlated spin systems can be driven to quantum critical points via various routes. In particular, gapped quantum antiferromagnets can undergo phase transitions into a magnetically ordered state with applied pressure or magnetic…
Quantum phase transitions are among the most intriguing phenomena that can occur when the electronic ground state of correlated metals are tuned by external parameters such as pressure, magnetic field or chemical substitution. Such…
Quantum criticality describes the collective fluctuations of matter undergoing a second-order phase transition at zero temperature. It is being discussed in a number of strongly correlated electron systems. A prototype case occurs in 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,…
Ferromagnetic quantum criticality in clean metals has proven elusive due to fermionic soft modes that drive the transition first order. We show that non-centrosymmetric metals with a strong spin-orbit interaction provide a promising class…
We have studied the antiferromagnetic order -- disorder transition occurring at $T=0$ in a 2-layer quantum Heisenberg antiferromagnet as the inter-plane coupling is increased. Quantum Monte Carlo results for the staggered structure factor…