相关论文: Universal signatures of the metamagnetic quantum c…

With understood exceptions, conventional superconductivity does not coexist with long-range magnetic order[1]. In contrast, unconventional superconductivity develops near a boundary separating magnetically ordered and magnetically…

CeRu2Si2 and CeRh2Si2 are two similar heavy fermion stoichiometric compounds located on the two sides of the magnetic quantum critical phase transition. CeRh2Si2 is an antiferromagnet below T_N=36 K with moderate electronic masses whereas…

We report the observation of multiple magnetic transitions in single crystals of EuPtAs using magnetization, transport, and thermodynamic measurements. EuPtAs crystallizes in the noncentrosymmetric tetragonal LaPtSi-type structure (space…

YbRh2Si2 is a model system for quantum criticality. Particularly, Hall effect measurements helped identify the unconventional nature of its quantum critical point. Here, we present a high-resolution study of the Hall effect and…

Kinetic properties of a two dimensional model of fermions interacting with antiferromagnetic spin excitations near the quantum critical point (QCP) are considered. The temperature or doping are assumed to be sufficiently high, such that the…

Deconfined quantum criticality of two-dimensional $SU(2)$ quantum antiferromagnets featuring a transition from an antiferromagnetically ordered ground state to a so-called valence-bond solid state, is governed by a non-compact CP$^1$ model…

Despite several decades of both experimental and theoretical work the nature of the hidden order transition at THO = 17.5 K in URu2Si2 remains enigmatic. We report here low field DC magnetization as well as AC susceptibility measurements…

The possibility of a zero temperature, altermagnetic instability in anisotropic two dimensional electron systems in the diffusive regime is analyzed, in the presence and absence of spin-orbit coupling. Allowing for ferromagnetism, a phase…

Unconventional metallic states which do not support well defined single-particle excitations can arise near quantum phase transitions as strong quantum fluctuations of incipient order parameters prevent electrons from forming coherent…

The existence of multiple energy scales is regarded as a signature of the Kondo breakdown mechanism for explaining the quantum critical behavior of certain heavy fermion compounds, like YbRh$_{2}$Si$_{2}$. The nature of the intermediate…

The rearrangement of single-particle degrees of freedom of a dilute two-dimensional electron gas in the vicinity of the quantum critical point is examined within a microscopic approach. It is shown that just beyond the critical point, the…

Since the seminal ideas of Berezinskii, Kosterlitz and Thouless, topological excitations are at the heart of our understanding of a whole novel class of phase transitions. In most of the cases, those transitions are controlled by a single…

The main properties and the type of the field-tuned quantum critical point in the heavy-fermion metal CeCoIn$_5$ arisen upon applying magnetic fields $B$ are considered within the scenario based on the fermion condensation quantum phase…

Quantum phase transitions are central to our understanding of why matter at very low temperatures can exhibit starkly different properties upon small changes of microscopic parameters. Accurately locating those transitions is challenging…

In the quest to realize a quantum spin liquid (QSL), magnetic long-range order is hardly welcome. Yet it can offer deep insights into a complex world of strong correlations and fluctuations. Much hope was placed in the cubic pyrochlore…

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…

The appearance of magnetization during the application of mechanical stress and the creation of elastic deformation during the application of a magnetic field are two fundamental properties of piezomagnetic materials. The symmetry of…

Understanding the nature of field-tuned metamagnetic quantum criticality in the ruthenate Sr3Ru2O7 has presented a significant challenge within condensed matter physics. It is known from experiments that the entropy within the ordered phase…

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…

Simultaneous resistivity and a.c.-specific heat measurements have been performed under pressure on single crystalline CeCu2Si2 to over 6 GPa in a hydrostatic helium pressure medium. A series of anomalies were observed around the pressure…