Publications de Balazs Sipos | EPFL Graph Search

Superconducting phase in the layered dichalcogenide 1T-TaS_{2} upon inhibition of the metal-insulator transition

Helmuth Berger, László Forró, Marco Grioni, Balazs Sipos, Julian Piatek, Ping-Hui Lin, Peng Xu, Henrik Moodysson Rønnow

When a Mott metal-insulator transition is inhibited by a small amount of disorder in the layered dichalcogenide 1T-TaS2, an inhomogeneous superconducting state arises below T=2.1 K and coexists with a nearly commensurate charge-density wave. By angle-resol ...

2010

A Neutral Zwitterionic Molecular Solid

László Forró, Bálint Náfrádi, Balazs Sipos

We report on the acid ethylenedithiotetrathiafulvaleneamidoglycine (EDT-TTF-CO-NH-CH2-CO2H; 1; EDT-TTF=ethylenedithiotetrathiafulvalene) and the 1:1 adduct [(EDT-TTF)(center dot+) -CO-NH-CH2-(CO2H)(-)][(EDT-TTF)-CO-NH-CH2-(CO2H)]center dot CH3OH (2), a new ...

2010

Pressure Induced Superconductivity in Pristine 1T-TiSe2

Helmuth Berger, László Forró, Eduard Tutis, Balazs Sipos

The interplay between superconductivity and the charge-density wave (CDW) state in pure 1T-TiSe2 is examined through a high-pressure study extending up to pressures of 10 GPa between sub-Kelvin and room temperatures. At a critical pressure of 2 GPa a super ...

2009

Mechanical and electronic properties of vanadium oxide nanotubes

László Forró, Andras Kis, Neven Barisic, Jin Won Seo, Arnaud Magrez, Balazs Sipos, Martial Duchamp

Vanadium oxide nanotubes with a diameter of 20-100 nm and an aspect ratio of 50-100 were synthesized by hydrothermal method. Young's modulus of 20-80 GPa was obtained by bending measurements of individual nanotubes using an atomic force microscope. Electri ...

American Institute of Physics2009

From Mott state to superconductivity in 1T-TaS2

Helmuth Berger, László Forró, Eduard Tutis, Ana Akrap, Balazs Sipos

The search for the coexistence between superconductivity and other collective electronic states in many instances promoted the discovery of novel states of matter. The manner in which the different types of electronic order combine remains an ongoing puzzl ...

2008

Normal state transport properties of novel superconductors

Balazs Sipos

The discovery of high temperature superconductivity in the cuprates in 1986 has boosted the research in strongly correlated materials. One strong motivation was and stays the understanding the high-Tc phenomenon with the hope that one can ultimately engine ...

EPFL2008

Matthiessen's rule in MgB2: Resistivity and T-c as a function of point defect concentration

László Forró, Richard Gaal, Neven Barisic, Balazs Sipos, Janusz Andrzej Karpinski

We present the results of a systematic study of the temperature-dependent resistivity and of T-c of a single crystal MgB2 sample as a function of point defect concentration. We have found linear, albeit weak, correlation between the decreasing superconduct ...

2007

High-pressure infrared spectroscopy: Tuning of the low-energy excitations in correlated electron systems

Helmuth Berger, László Forró, Richard Gaal, Balazs Sipos

We have extended the range of the high-pressure optical spectroscopy to the far-infrared region keeping the accuracy of ambient-pressure experiments. The developed method offers a powerful tool for the study of pressure-induced phase transitions and electr ...

2007