Multidimensional entropy landscape of quantum criticality

Abstract

The Third Law of Thermodynamics states that the entropy of any system in equilibrium has to vanish at absolute zero temperature. At nonzero temperatures, on the other hand, matter is expected to accumulate entropy near a quantum critical point (QCP), where it undergoes a continuous transition from one ground state to another. Here, we determine, based on general thermodynamic principles, the spatial-dimensional profile of the entropy S near a QCP and its steepest descent in the corresponding multidimensional stress space. We demonstrate this approach for the canonical quantum critical compound CeCu6-xAux near its onset of antiferromagnetic order. We are able to link the directional stress dependence of S to the previously determined geometry of quantum critical fluctuations. Our demonstration of the multidimensional entropy landscape provides the foundation to understand how quantum criticality nucleates novel phases such as high-temperature superconductivity.

arXiv comment14 pages, 4 figures

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Cited by in corpus (11)

• Heavy-electron quantum criticality and single-particle spectroscopy
• Frustration and quantum criticality
• Quantum Ising model on the frustrated square lattice
• Crossovers and critical scaling in the one-dimensional transverse-field Ising model
• Evolution of charge density wave order and superconductivity under pressure in LaPt${}_2$Si${}_2$
• Uniaxial stress tuning of geometrical frustration in a Kondo lattice
• Quantum critical point in the itinerant ferromagnet Ni${}_{1-x}$Rh${}_x$
• Quantum critical metals and loss of quasiparticles
• Magnetic and structural quantum phase transitions in CeCu6-xAux are independent
• Non-Divergent Grüneisen Parameter in Quantum Critical Quasicrystal Yb${}_{15}$Al${}_{34}$Au${}_{51}$: Reflection of Robustness of Quantum Criticality under Pressure
• Quantum criticality in the spin-isotropic pseudogap Bose-Fermi Kondo model: entropy, scaling, and the g-theorem