P. V. Parimi

Focusing by Plano-Concave lens using Negative Refraction (2005)

Vodo, P., Parimi, P. V., Lu, W. T., Sridhar, S.

We demonstrate focusing of a plane microwave by a plano-concave lens fabricated from a photonic crystal (PhC) having negative refractive index and left-handed electromagnetic properties. An inverse...

Microwave photonic crystal with tailor-made negative refractive index (2004)

Vodo, P., Parimi, P. V., Lu, W. T., Wing, R., Sridhar, S.

Negative refraction and left-handed electromagnetism in a metallic photonic crystal (PC) wedge are demonstrated in free space for both transverse magnetic and electric mode propagation. The...

Negative Refraction and Left-handed electromagnetism in Microwave Photonic Crystals (2003)

Parimi, P. V., Lu, W. T., Vodo, P., Sokoloff, J., Sridhar, S.

We demonstrate negative refraction of microwaves in metallic photonic crystals. The spectral response of the photonic crystal, which manifests both positive and negative refraction, is in complete...

Dielectric signatures of lattice instabilities at 32K and 245K in $La_{2-y}Sr_{y}MO_{4+x}$ (M=Cu,Ni) Cuprates and Nickelates (2001)

Parimi, P. V., Hakim, N., Chou, F. C., Cheong, S. W., Sridhar, S.

New dielectric transitions are observed at common temperatures 32K and 245K, in isostructural $La_{2}CuO_{4+x}$ and $La_{5/3}Sr_{1/3}NiO_{4},$ that are signatures of local lattice (octahedral)...

Microwave properties of superconducting $MgB_{2}$ (2001)

Hakim, N., Parimi, P. V., Kusko, C., Sridhar, S., Canfield, P. C., Bud'ko, S. L., ...

Measurements of the $10GHz$ microwave surface resistance of dense $MgB_{2}$ wire and pellet are reported. Significant improvements are observed in the wire with reduction of porosity. The data lie...

rf susceptibility of La_{1-x}Sr_{x}MnO_{3} single crystals : magnetic signatures of structural changes (2000)

Parimi, P. V., Srikanth, H., Bailleul, M., Sridhar, S., Suryanarayanan, R., Pinsard, L., ...

A sensitive tunnel diode oscillator (TDO) operating at 4MHz is used to probe the dynamic response of La_{1-x}Sr_{x}MnO_{3} single crystals for x=0.125,0.175,0.28 and 0.33 doping. Systematics of the...

Onset of dielectric modes at 110K and 60K due to local lattice distortions in non-superconducting YBa_{2}Cu_{3}O_{6.0} crystals (2000)

Zhai, Z., Parimi, P. V., Sokoloff, J. B., Erb, A., Sridhar, S.

We report the observation of two dielectric transitions at 110K and 60K in the microwave response of non-superconducting YBa_{2}Cu_{3}O_{6.0} crystals. The transitions are characterized by a change...