Comprehensive phase diagram of two-dimensional space charge doped Bi2Sr2CaCu2O8+x

Keywords: Superconductivity, High-Tc superconductors, Phase Diagram, 2D materials. 

The phase diagram of hole-doped high critical temperature superconductors as a function of doping and temperature has been intensively studied with chemical variation of doping. Chemical doping can provoke structural changes and disorder, masking intrinsic effects. Alternatively a field-effect transistor geometry with an electrostatically doped, ultra-thin sample can be used. However to probe the phase diagram, carrier density modulation beyond 1014cm-2 and transport measurements performed over a large temperature range are needed. Here we use the space charge doping method1,2 to measure transport characteristics from 330~K to low temperature. We extract parameters and characteristic temperatures over a large doping range and establish a comprehensive phase diagram for one unit cell thick Bi2Sr2CaCu2O8+x as a function of doping, temperature and disorder3. 

1. Johan Biscaras et al., Nature Comm. 6, 8826 (2015) 
2. A. Paradisi et al., Applied Physics Letters 107, 143103 (2015). 
3. E.Sterpetti et al., Nature Comm. 8, 2060 (2017)