Victor Barzykin

Superconductivity in an Organic Insulator at Very High Magnetic Fields

We investigate by electrical transport the field-induced superconducting state (FISC) in the organic conductor lambda-(BETS)2FeCl4. Below 4 K, antiferromagnetic-insulator, metallic, and eventually superconducting (FISC) ground states are observed with increasing in-plane magnetic field. The FISC state survives between 18 and 41 T and can be interpreted in terms of the Jaccarino-Peter effect, where the external magnetic field compensates the exchange field of aligned Fe3+ ions. We further argue that the Fe3+ moments are essential to stabilize the resulting singlet, two-dimensional superconducting state.

CONVENTIONAL MECHANISMS FOR EXOTIC SUPERCONDUCTIVITY

We consider the pairing state due to the usual BCS mechanism in substances of cubic and hexagonal symmetry where the Fermi surface forms pockets around several points of high symmetry. We find that the symmetry imposed on the multiple pocket positions could give rise to a multidimensional nontrivial superconducting order parameter. The time-reversal symmetry in the pairing state is broken. We suggest several candidate substances where such ordering may appear, and discuss means by which such a phase may be identified.

Singlet magnetism in heavy fermions.

We consider singlet magnetism for the uranium ions in UPt

The Kondo screening cloud: What can we learn from perturbation theory?

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Universal behaviour and the two-component character of magnetically underdoped cuprate superconductors

and URu

The emerging picture of ferromagnetism in the divalent hexaborides

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Role of striction at magnetic and structural transitions in iron pnictides

Si

SCREENING CLOUD IN THE K-CHANNEL KONDO MODEL : PERTURBATIVE AND LARGE-K RESULTS

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Phenomenological model of protected behavior in the pseudogap state of underdoped cuprate superconductors.

assuming that time-reversal symmetry is broken for the {\em coherent state of intermediate valence}. The relative weight of the two involved configurations should be different for UPt

Exotic ground states and impurities in multiband superconductors

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