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A V Silhanek

Publications and source records attributed to A V Silhanek.

4 recordsLinked to original sources
PubMed2006

Nonlocal magnetic field-tuned quantum criticality in cubic CeIn(3-x)Sn(x) (x = 0.25).

We show that antiferromagnetism in lightly (approximately 8%) Sn-doped CeIn3 terminates at a critical field mu0H(c) = 42 +/- 2 T. Electrical transport and thermodynamic measurements reveal the effective mass m* not to diverge, suggesting that cubic CeIn3 is representative of a critical spin-density wave (SDW) scenario, unlike the local quantum critical points reported in anisotropic systems such as CeCu(6-x)Au(x) and YbRh2Si(2-x)Ge(x). The existence of a maximum in m* at a lower field mu0H(x) = 30 +/- 1 T may be interpreted as a field-induced crossover from local moment to SDW behavior as the Néel temperature falls below the Fermi temperature.

Journal Article↗
PubMed2006

Irreversible dynamics of the phase boundary in U(Ru0.96Rh0.04)2Si2 and implications for ordering.

We report measurements and analysis of the specific heat and magnetocaloric effect-induced temperature changes at the phase boundary into the single magnetic field-induced phase (phase II) of U(Ru0.96Rh0.04)2Si2, which yield irreversible properties similar to those at the valence transition of Yb(1-x)Y(x)InCu4. To explain these similarities, we propose a bootstrap mechanism by which lattice parameter changes caused by an electric quadrupolar order parameter within phase II become coupled to the 5f-electron hybridization, giving rise to a valence change at the transition.

Journal Article↗
PubMed2005

Quantum critical 5f electrons avoid singularities in U(Ru,Rh)2Si2.

We present specific heat measurements of 4% Rh-doped URu2Si2 at magnetic fields around the proposed metamagnetic transition field H(m) approximately 34 T, revealing striking similarities to the isotructural Ce analog CeRu2Si2 for H>H(m). This suggests that strongly renormalized hybridized-band models apply equally well to both systems. The vanishing bandwidths as H-->H(m) are consistent with a quantum-critical point close to H(m). The existence of a phase transition into an ordered phase in the vicinity of H(m) for 4% Rh-doped URu2Si2, but not for CeRu2Si2, is consistent with a stronger superexchange in the case of the U 5f system. Irreversible processes at the transition indicate a strong coupling of the 5f orbitals to the lattice, most suggestive of electric quadrupolar order.

Journal Article↗