Pressure induced enhancement of CDW fluctuations in 1T-TiSe2

1T-TiSe2 is atypical quasi 2-dimensional CDW material showing a 2x2x2 superlattice modulation at low temperature. It's is known that high pressure suppresses the CDW order and interestingly induces superconductivity. While it is not agreed what drives the CDW transition, it has been proposed that the CDW fluctuations are closely related to the emergence of superconductivity . Here we present a detailed high pressure X-ray diffraction study of the CDW order in -TiSe2. We can directly probe not only the order parameter but also the fluctuations of the CDW order. At low pressure we observe no sizable deviation from mean field predictions. For pressures above around 2.5GPa, however, we observe changes in the CDW line shape, indicating enhanced CDW fluctuations. Those results are consistent with previous high pressure transport measurements and suggest a relationship between the superconductivity and the charge density wave in this system.