PREPRINTS

[22] Superfluid-like TO Responses in Rotating Solid Helium
      J. Choi, T. Tsuiki, D. Takahashi, H. Choi, K. Kono, K. Shirahama and E. Kim 
     arXiv:1701.07190 (under review)
 

[21] Scailing Analysis of Field-tuned Superconductor-insulator Transition in
      Two-dimensional Tantalium Thin Film
      S. Park, J. Shin and E. Kim
      Scientific Reports 7, 42929 (2017)
 
[20] Simultaneous Investigation of Shear Modulus and Torsional Resonance of       Solid 4He
      J. Shin, J. Choi, K. Shirahama and E. Kim
      Physical Review B 93, 214512 (2016)
   
[19] Evolution of Various Quantum Transport Properties in a Suspended
      Disordered Graphene Device by the High Bias Voltage Exposure
      J. I. Lee, S. Jang, S. Cho and E. Kim
      Current Applied Physics 16, 731 (2016)
    
[18] Frequency-dependent Study of Solid He4 Contained in a Rigid Double-
      torus Torsional Oscillator
      J. Choi, J. Shin and E. Kim
      Physical Review B 92, 144505 (2015)
   
[17] Modified Granato-Lucke Theory with Pinning Length Distribution
      in Solid 4He
      E. S. H. Kang, H. Yoon, and E. Kim
      Journal of the Physical Society of Japan 84, 034602 (2015)
  
[16] Multi-barrier Field-emission Behavior in PBTTT Thin Films at Low
      Temperatures
      E. S. H. Kang, and E. Kim
      Scientific Reports 5, 8396 (2015)
  
[15] Stress- and Temperature-dependent Hysteresis of the Shear
      Modulus of Solid 4He
      E. S. H. Kang, D. Y. Kim, H. C. Kim, and E. Kim
      Physical Review B 87, 094512 (2013)
  
[14] Shear Resonance and Torsional Oscillator Measurements of Solid
      4He under DC Rotation
      W. Choi, D. Takahashi, D. Y. Kim, H. Choi, K. Kono and E. Kim
      Physical Review B 86, 174505 (2012)
  
[13] Staircaselike Suppression of Supersolidity under Rotation
      H. Choi, D. Takahashi, K. Kono and E. Kim
      Physical Review Letters 108, 105302 (2012)
  
[12] Effect of Non-isothermal Recrystallization on Microstrucutre and
      Transport in Poly(thieno-thiophene) Thin Films
      E. S. H. Kang, and E. Kim
      Organic Electronics 12, 1649-1656 (2011)
  
[11] Unaffected Nonclassical Response of Solid 4He under Elastic
      Modulus Variation
      D. Y. Kim, H. Choi, W. Choi, S. Kwon, E. Kim and H. C. Kim
      Physcal Review B 83, 052503 (2011)
  
[10] Evidence of Supersolidity in Rotating Solid Helium
      H. Choi, D. Takahashi, K. Kono, and E. Kim
      Science 330, 1512-1515 (2010)
  
[9] Observation of Hidden Phases in Supersolid 4He
      H. Choi, S. Kwon, D. Y. Kim and E. Kim
      Nature Physics 6, 424-427 (2010)
  
[8] Amorphous Dithenylcyclopentadienone-carbazole Copolymers for       Organic Thin-film Transistor
      E. S. H. Kang, J. D. Yuen, W. Walker, N. E. Coates, S. Cho, E. Kim and F. Wudl
      Journal of Materials Chemistry 20, 2759-2765 (2010)
  
[7] Non-classical Response from Quench-cooled Solid Helium Confined
      in a Porous Gold
      D. Y. Kim, S. Kwon, H. Choi, H. C. Kim, and E. Kim
      New Journal of Physics 12, 033004 (2010)
  
[6] Absence of Slow Sound Modes in Supersolid 4He
      S. Kwon, N. Mulders, and E. Kim
      Journal of Low Temperature Physics 158, 590-595 (2010)
  
[5] Effect of He3 Impurities on the Nonclassical Response to
     Oscillation of Solid He4
      E. Kim, J. S. Xia, J. T. West, X. Lin, A. C. Clarck, and M. H. W. Chan
      Physical Review Letters 100, 065301 (2008)
  
[4] Supersolid Helium at High Pressure
      E. Kim and M. H. W. Chan
      Physcal Review Letters 97, 115302 (2006)
  
[3] Observation of Non-classical Rotational Inertia in Solid 4He
      Confined in Porous Gold
      E. Kim and M. H. W. Chan
      Journal of Low Temperature Physics 138, 859-864 (2005)
  
[2] Observation of Superflow in Solid Helium
      E. Kim and M. H. W. Chan
      Science 305, 1941-1944 (2004)
  
[1] Probable Observation of a Supersolid Helium Phase
      E. Kim and M. H. W. Chan
      Nature 427, 225-227 (2004)

Non-classical Rotational Inertia and Shear Modulus of Solid Helium Download

Non-classical Rotational Inertia and Acoustic Resonance Studies of Solid Helium under  Rotation Download

Quantum Phase Transition of 2D Tantalium Thin Film Tuned by B-field, Disorder, and Effect of DC Bias Download

Low-temperature Transport in Semiconducting Polymer Thin Films Download

The Electronic Transport Properties of High-Bias-Voltage-Exposed Graphene Devices Download

Simultaneous Investigation of Shear Modulus and Torsional Resonance of Polycrystalline Solid Helium-4 Download

Search for Supersolid Helium by Using a Rigid Torsional Oscillator Download

The superconductor–insulator (SI) transition in two-dimensional Ta thin films is investigated by controlling both film thickness and magnetic field. An intriguing metallic phase appears between a superconducting and an insulating phase within a range of film thickness and magnetic field. The temperature and electric field scaling analyses are performed to investigate the nature of the SI transition in the thickness-tuned metallic and superconducting samples. The critical exponents product of νz obtained from the temperature scaling analysis is found to be approximately 0.67 in the entire range of film thickness. On the other hand, an apparent discrepancy is measured in the product of ν(z+1) by the electric filed analysis. The product values are found to be about 1.37 for the superconducting films and about 1.86 for the metallic films respectively. We find that the discrepancy is the direct consequence of electron heating that introduces additional dissipation channels in the metallic Ta films.

We investigate the origin of a resonant period drop of a torsional oscillator (TO) containing solid He4 by inspecting its relation to a change in elastic modulus. To understand this relationship directly, we measure both phenomena simultaneously using a TO with a pair of concentric piezoelectric transducers inserted in its annulus. We confirm experimentally that both anomalies are directly related. Although the temperature, He3 concentration, and frequency dependence are essentially the same, a marked discrepancy in the drive amplitude dependence is observed. We find that this discrepancy originates from the anisotropic response of polycrystalline solid He4 connected with low-angle grain boundaries by studying the shear modulus parallel to and perpendicular to the driving direction.