The high temperature superconductors which were discovered in 1986 still continue to pose major challenges to scientists. Not only is the mechanism for superconductivity not known, but the nature of the superconducting state and the motion of vortices continue to be debated intensely. We study the microwave response of superconductors, both for understanding the nature of superconductivity, the dynamics of vortices and for practical applications in microwave devices.

The principal areas of our research are:

  • Fundamental measurements and analysis of the penetration depth and surface impedance of superconductors, with a view to understanding the pairing state, the quasiparticle spectrum and the gap parameter
  • Vortex dynamics at high (rf and microwave) frequencies to obtain quantiative measurements of parameters such as pinning force constants, vortex viscosity, critical fields, melting and vortex glass transitions
  • Flux penetration and critical state dynamics
  • Josephson type nonlinear phenomena at microwave frequencies
  • Development of novel measurement techniques, such as the “hot finger” cavity method to measure surface impedance, tunnel diode technique of measuring penetration depth, patterned film structures to study vortex dynamics, modulated microwave absorption

The materials we study are the cuprate High Tc superconductors, borocarbides, and organic superconductors.

Our work in Superconductivity is supported by:

  • National Science Foundation
  • Division of Materials Research and Division of Electrical and Communications Systems, Rome Laboratory, Hanscom AFB (an AFOSR lab)

Related Publications

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Faegh, Samira; Jalili, Nader; Sridhar, Srinivas

Sensor system utilizing piezoelectric microcantilever coupled with resonating circuit Miscellaneous

2018, (US Patent 9,921,226).

Abstract | Tags: Sensors

Ozturk, Birol; Yavuzcetin, Ozgur; Sridhar, Srinivas

A novel coupled resonator photonic crystal design in lithium niobate for electrooptic applications Journal Article

In: International Journal of Optics, vol. 2015, 2015.

Abstract | Tags: Nanomedicine, Sensors

Faegh, Samira; Jalili, Nader; Sridhar, Srinivas

Ultrasensitive piezoelectric-based microcantilever biosensor: Theory and experiment Journal Article

In: IEEE/ASME Transactions on Mechatronics, vol. 20, no. 1, pp. 308–312, 2014.

Abstract | Tags: Sensors

Yavuzcetin, O; Perry, Nicholas R; Malley, Sean T; Dally, Rebecca L; Novikov, Herman P; Ozturk, Birol; Sridhar, Srinivas

Fabrication and characterization of single mode annealed proton exchanged waveguides in-x-cut lithium niobate Journal Article

In: Optical Materials, vol. 36, no. 2, pp. 372–375, 2013.

Abstract | Tags: Sensors

Faegh, Samira; Jalili, Nader; Yavuzcetin, Ozgur; Nagesha, Dattatri; Kumar, Rajiv; Sridhar, Srinivas

A cost-effective self-sensing biosensor for detection of biological species at ultralow concentrations Journal Article

In: Journal of Applied Physics, vol. 113, no. 22, pp. 224905, 2013.

Abstract | Tags: Sensors

Yavuzcetin, Ozgur; Novikov, Herman P; Dally, Rebecca L; Malley, Sean T; Perry, Nicholas R; Ozturk, Birol; Sridhar, Srinivas

Photonic crystal fabrication in lithium niobate via pattern transfer through wet and dry etched chromium mask Journal Article

In: Journal of Applied Physics, vol. 112, no. 7, pp. 074303, 2012.

Abstract | Tags: Sensors

Sridhar, Srinivas; Gultepe, Evin; Nagesha, Dattatri

Large scale nanoelement assembly method for making nanoscale circuit interconnects and diodes Miscellaneous

2011, (US Patent App. 12/936,938).

Abstract | Tags: Sensors

Yavuzcetin, Ozgur; Ozturk, Birol; Xiao, Dong; Sridhar, Srinivas

Conicity and depth effects on the optical transmission of lithium niobate photonic crystals patterned by focused ion beam Journal Article

In: Optical Materials Express, vol. 1, no. 7, pp. 1262–1271, 2011.

Abstract | Tags: Sensors

Selvarasah, S; Chao, SH; Chen, C-L; Sridhar, S; Busnaina, A; Khademhosseini, A; Dokmeci, MR

A reusable high aspect ratio parylene-C shadow mask technology for diverse micropatterning applications Journal Article

In: Sensors and Actuators A: Physical, vol. 145, pp. 306–315, 2008.

Abstract | Tags: Sensors

Sridhar, Srinivas

This event is cosponsored by the Central New England Chapter of the IEEE Lasers and Electro-Optics Society as part of the LEOS 30 th Anniversary Celebration Journal Article

In: 2007.

Abstract | Tags: Sensors

Selvarasah, S; Chao, SH; Chen, C-L; Mao, D; Hopwood, J; Ryley, S; Sridhar, S; Khademhosseini, A; Busnaina, A; Dokmeci, MR

A high aspect ratio, flexible, transparent and low-cost parylene-C shadow mask technology for micropatterning applications Inproceedings

In: TRANSDUCERS 2007-2007 International Solid-State Sensors, Actuators and Microsystems Conference, pp. 533–536, IEEE 2007.

Abstract | Tags: Sensors

Selvarasah, Selvapraba; Makaram, Prashanth; Chen, Chia-Ling; Xiong, Xugang; Chao, Shih-Hsien; Busnaina, Ahmed; Sridhar, Srinivas; Dokmeci, Mehmet R

A three dimensional multi-walled carbon nanotube based thermal sensor on a flexible parylene substrate Inproceedings

In: 2007 7th IEEE Conference on Nanotechnology (IEEE NANO), pp. 1062–1066, IEEE 2007.

Abstract | Tags: Sensors

Parikh, A; Yarbrough, W; Mason, M; Sridhar, S; Chidambaram, PR; Cai, Z

Characterization of structure and morphology of an advanced p-channel field effect transistor under uniaxial stress by synchrotron x-ray diffraction Journal Article

In: Applied physics letters, vol. 90, no. 17, pp. 172117, 2007.

Tags: Sensors

Sridhar, S; Giannakopoulos, AE; Suresh, S; Ramamurty, U

CONDENSED MATTER: Dielectric and Optical Properties (PACS 77-79)-Electrical response during indentation of piezoelectric materials: A new method for material characterization Journal Article

In: Journal of Applied Physics, vol. 85, no. 1, pp. 380–387, 1999.

Tags: Sensors

Selvarasah, S; Banyal, R; Casse, BDF; Lu, WT; Sridhar, S; Dokmeci, MR

Design and implementation of silicon-based optical nanostructures for integrated photonic circuit applications using Deep Reactive Ion Etching (DRIE) technique Journal Article

In: 0000.

Abstract | Tags: Sensors