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

Show all

Qiao, Ju; Cai, Xuezhu; Xiao, Qian; Chen, Zhengxi; Kulkarni, Praveen; Ferris, Craig; Kamarthi, Sagar; Sridhar, Srinivas

Data on MRI brain lesion segmentation using K-means and Gaussian Mixture Model-Expectation Maximization Journal Article

In: Data in brief, vol. 27, pp. 104628, 2019.

Abstract | Tags: MRI

Thanh, Nguyen; Phuc, Xuan; Sridhar, Srinivas

Nanoscale Magnetism in Next Generation Magnetic Nanoparticles Technical Report

UNIVERSITY COLLEGE LONDON London United Kingdom 2018.

Abstract | Tags: MRI, Nanomedicine

Codi, Gharagouzloo; Qiao, Ju; Timms, Liam; van de Ven, Anne; Sridhar, Srinivas

Abstract B22: Quantitative tumor imaging using magnetic nanoparticles Miscellaneous


Abstract | Tags: MRI

Gharagouzloo, Codi A; Timms, Liam; Qiao, Ju; Fang, Zihang; Nneji, Joseph; Pandya, Aniket; Kulkarni, Praveen; van de Ven, Anne L; Ferris, Craig; Sridhar, Srinivas

Quantitative vascular neuroimaging of the rat brain using superparamagnetic nanoparticles: New insights on vascular organization and brain function Journal Article

In: Neuroimage, vol. 163, pp. 24–33, 2017.

Abstract | Tags: MRI

Gharagouzloo, Codi; Sridhar, Srinivas

Quantitative magnetic resonance imaging of the vasculature Miscellaneous


Abstract | Tags: MRI

Wang, Haotian; Kumar, Rajiv; Nagesha, Dattatri; Jr, Richard I Duclos; Sridhar, Srinivas; Gatley, Samuel J

Integrity of 111In-radiolabeled superparamagnetic iron oxide nanoparticles in the mouse Journal Article

In: Nuclear medicine and biology, vol. 42, no. 1, pp. 65–70, 2015.

Abstract | Tags: MRI, Nanomedicine

Gharagouzloo, Codi Amir; McMahon, Patrick N; Sridhar, Srinivas

Quantitative contrast-enhanced MRI with superparamagnetic nanoparticles using ultrashort time-to-echo pulse sequences Journal Article

In: Magnetic resonance in medicine, vol. 74, no. 2, pp. 431–441, 2015.

Tags: MRI, Nanomedicine

Sridhar, S; Kumar, Rajesh P; Ramanaiah, KV

Wavelet Transform Techniques for Image Compression-An Evaluation Journal Article

In: International journal of image, graphics and signal processing, vol. 6, no. 2, pp. 54, 2014.

Abstract | Tags: MRI

Gharagouzloo, CA; Madi, S; Seethamraju, RT; Harisinghani, M; Sridhar, S

Ultrashort TE imaging with SPIONs: bright prospects for in vivo applications Inproceedings


Tags: MRI

Gharagouzloo, Codi; Jillela, Manasa; Kumar, Rajiv; Nagesha, Dattatri; Sridhar, Srinivas

Positive contrast imaging of magnetic nanoplatforms for image-guided drug delivery. Miscellaneous


Abstract | Tags: MRI

Sridhar, Srinivas; Campbell, Robert; Nagesha, Dattatri; Gultepe, Evin

Magnetic nanoplatforms for tumor targeting, imaging and energy delivery Miscellaneous


Abstract | Tags: MRI

Sawant, RM; Nagesha, D; Sridhar, S; Torchilin, VP

Polymeric Magnetomicelles As a Probe for MRI Imaging: Characterization and Mri Properties Journal Article

In: 0000.

Abstract | Tags: MRI

Gharagouzloo, Codi Amir; Ma, Chao; Verwer, Eline E; Mandeville, Joseph B; Huang, Chuan; Sridhar, Srinivas; Fakhri, Georges El; Wooten, Dustin W; Normandin, Marc D

Functional neuroimaging using dynamic radial 3D UTE pulse sequences Journal Article

In: 0000.

Abstract | Tags: MRI

Sawant, RM; Gultepe, E; Nagesha, D; Sridhar, S; Torchilin, VP

Developing superparamagnetic iron oxide nanoparticles as tumor-specific magnetic resonance imaging (MRI) contrast agents Journal Article

In: 0000.

Abstract | Tags: MRI