The critical state in Bi2Sr2CaCu2O single crystals is found to become unstable at low temperature... more The critical state in Bi2Sr2CaCu2O single crystals is found to become unstable at low temperatures and high magnetic fields. Reproducible and almost periodic flux jumps developed at high fields only are qualitatively different from those known in conventional superconductors and predicted by existing models. The breakdown can occur in the regime considered to be stable, which compromises the existing criteria for the potential high-field applications of high-Tc materials.
Extremely fast rotating molecules carrying significantly more energy in their rotation than in an... more Extremely fast rotating molecules carrying significantly more energy in their rotation than in any other degree of freedom are known as "super rotors". It has been speculated that super rotors may exhibit a number of unique properties. Theoretical studies showed that ultrafast molecular rotation may change the character of molecular scattering from solid surfaces, alter molecular trajectories in external fields, make super rotors stable against collisions, and lead to the formation of gas vortices. New ways of molecular cooling and selective chemical bond breaking by ultrafast spinning have been suggested. Bringing a large number of molecules to fast, directional and synchronous rotation is rather challenging. An efficient method of accelerating molecular rotation with an "optical centrifuge" has been proposed and successfully implemented, yet only indirect evidence of super rotors has been reported to date. Here we demonstrate the first direct observation of mol...
Using an optical centrifuge to control molecular rotation in extremely broad range of angular mom... more Using an optical centrifuge to control molecular rotation in extremely broad range of angular momenta, we study coherent rotational dynamics of nitrogen molecules in the presence of dissipation. Our detection technique of time- and frequency-resolved Raman scattering allows us to analyze the decay rate of rotational coherence as a function of the rotational quantum number between $J=6$ and $J=66$. We demonstrate that the rate of rotational decoherence can be varied by more than an order of magnitude in the studied range of $J$ values. The dependence of the decoherence rate on $J$, pressure and temperature is in good agreement with the "energy corrected sudden" (ESC) model of collisional decay.
Magnetoresistance (MR) ratios R(B,T)/R(0,T) have been measured in an insulating three-dimensional... more Magnetoresistance (MR) ratios R(B,T)/R(0,T) have been measured in an insulating three-dimensional amorphous nickel-silicon film that exhibits the Mott variable-range hopping (VRH) law in its zero-field resistance behavior. Surprisingly, the resistance displayed a decrease in small ...
Bulletin of the Russian Academy of Sciences: Physics, 2007
ABSTRACT Dichroism of linearly polarized light propagating along the tetragonal C 4 axis, induced... more ABSTRACT Dichroism of linearly polarized light propagating along the tetragonal C 4 axis, induced by a longitudinal magnetic field, has been revealed in a tetragonal antiferromagnetic manganese fluoride crystal in the region of optical transitions. The magnetic linear dichroism observed is proportional to the magnetic field strength and odd with respect to the field sign. The value of the effect is sufficient for optical observation of antiferromagnetic domains in MnF2 crystals.
Magnetic circular dischorism (MCD) has been observed in YBa2Cu3O(7-x) films in the visible region... more Magnetic circular dischorism (MCD) has been observed in YBa2Cu3O(7-x) films in the visible region of the optical spectrum (275-825 nm). The MCD spectrum correlates with the absorption spectrum; it reaches (1-5) x 10 exp -4/T at extreme points. The dispersion and temperature dependences of MCD are different for superconducting and nonsuperconducting specimens.
The critical state in Bi2Sr2CaCu2O single crystals is found to become unstable at low temperature... more The critical state in Bi2Sr2CaCu2O single crystals is found to become unstable at low temperatures and high magnetic fields. Reproducible and almost periodic flux jumps developed at high fields only are qualitatively different from those known in conventional superconductors and predicted by existing models. The breakdown can occur in the regime considered to be stable, which compromises the existing criteria for the potential high-field applications of high-Tc materials.
Extremely fast rotating molecules carrying significantly more energy in their rotation than in an... more Extremely fast rotating molecules carrying significantly more energy in their rotation than in any other degree of freedom are known as "super rotors". It has been speculated that super rotors may exhibit a number of unique properties. Theoretical studies showed that ultrafast molecular rotation may change the character of molecular scattering from solid surfaces, alter molecular trajectories in external fields, make super rotors stable against collisions, and lead to the formation of gas vortices. New ways of molecular cooling and selective chemical bond breaking by ultrafast spinning have been suggested. Bringing a large number of molecules to fast, directional and synchronous rotation is rather challenging. An efficient method of accelerating molecular rotation with an "optical centrifuge" has been proposed and successfully implemented, yet only indirect evidence of super rotors has been reported to date. Here we demonstrate the first direct observation of mol...
Using an optical centrifuge to control molecular rotation in extremely broad range of angular mom... more Using an optical centrifuge to control molecular rotation in extremely broad range of angular momenta, we study coherent rotational dynamics of nitrogen molecules in the presence of dissipation. Our detection technique of time- and frequency-resolved Raman scattering allows us to analyze the decay rate of rotational coherence as a function of the rotational quantum number between $J=6$ and $J=66$. We demonstrate that the rate of rotational decoherence can be varied by more than an order of magnitude in the studied range of $J$ values. The dependence of the decoherence rate on $J$, pressure and temperature is in good agreement with the "energy corrected sudden" (ESC) model of collisional decay.
Magnetoresistance (MR) ratios R(B,T)/R(0,T) have been measured in an insulating three-dimensional... more Magnetoresistance (MR) ratios R(B,T)/R(0,T) have been measured in an insulating three-dimensional amorphous nickel-silicon film that exhibits the Mott variable-range hopping (VRH) law in its zero-field resistance behavior. Surprisingly, the resistance displayed a decrease in small ...
Bulletin of the Russian Academy of Sciences: Physics, 2007
ABSTRACT Dichroism of linearly polarized light propagating along the tetragonal C 4 axis, induced... more ABSTRACT Dichroism of linearly polarized light propagating along the tetragonal C 4 axis, induced by a longitudinal magnetic field, has been revealed in a tetragonal antiferromagnetic manganese fluoride crystal in the region of optical transitions. The magnetic linear dichroism observed is proportional to the magnetic field strength and odd with respect to the field sign. The value of the effect is sufficient for optical observation of antiferromagnetic domains in MnF2 crystals.
Magnetic circular dischorism (MCD) has been observed in YBa2Cu3O(7-x) films in the visible region... more Magnetic circular dischorism (MCD) has been observed in YBa2Cu3O(7-x) films in the visible region of the optical spectrum (275-825 nm). The MCD spectrum correlates with the absorption spectrum; it reaches (1-5) x 10 exp -4/T at extreme points. The dispersion and temperature dependences of MCD are different for superconducting and nonsuperconducting specimens.
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Papers by Alexander Milner