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Steven Simon

Publications and source records attributed to Steven Simon.

21 records · Page 2Linked to original sources

A Ham Sandwich Analogue for Quaternionic Measures and Finite Subgroups of S^3

A "ham sandwich" theorem is established for n quaternionic Borel measures on quaternionic space H^n. For each finite subgroup G of S^3, it is shown that there is a quaternionic hyperplane H and a corresponding tiling of H^n into |G| fundamental regions which are rotationally symmetric about H with respect to G, and satisfy the condition that for each of the n measures, the "G average" of the measures of these regions is zero. If each quaternionic measure is a 4-tuple of finite Borel measures on R^{4n}, the original ham sandwich theorem on R^{4n} is recovered when G = Z_2. The theorem applies to [n/4] finite Borel measures on R^n, and when G is the quaternion group Q_8 this gives a decomposition of R^n into 2 rings of 4 cubical "wedges" each, such that the measure any two opposite wedges is equal for each finite measure.

math.CO

Analysis of Trapped Quantum Degenerate Dipolar Excitons

The dynamics of quantum degenerate two-dimensional dipolar excitons confined in electrostatic traps is analyzed and compared to recent experiments. The model results stress the importance of artificial trapping for achieving and sustaining a quantum degenerate exciton fluid in such systems and suggest that a long-lived, spatially uniform, and highly degenerate exciton system was experimentally produced in those electrostatic traps.

cond-mat.other

Artificial trapping of a stable high-density dipolar exciton fluid

We present compelling experimental evidence for a successful electrostatic trapping of two-dimensional dipolar excitons that results in stable formation of a well confined, high-density and spatially uniform dipolar exciton fluid. We show that, for at least half a microsecond, the exciton fluid sustains a density higher than the critical density for degeneracy if the exciton fluid temperature reaches the lattice temperature within that time. This method should allow for the study of strongly interacting bosons in two dimensions at low temperatures, and possibly lead towards the observation of quantum phase transitions of 2D interacting excitons, such as superfluidity and crystallization.

cond-mat.str-el