Since the discovery of Anomalous Nernst effect in high-Tc cuprates, it has been discussed as a clue to the mechanism of superconductivity. Up to now, there are two explanations for the enhancement of Nernst signal. One is that the large Nernst signal is attributed to the movement of vortices which survives far above Tc. The other is that Nernst signal is enhanced by stripe order. The former supports the scenario that the superconducting gap opens far above Tc, although the long-range phase coherence is destroyed by vortex excitation. While the latter implies that the superconductivity occurs near the quantum critical point where the competing orders, such as stripe order and/or charge order, cross in the phase diagram.
Here, we controlled the strength (stability) of the stripe order, and measured the Nernst effect to investigate the effects of the charge (stripe) ordered state on Nernst signal. It is well known that Nd-doping in La2-xSrxCuO4 enhances the strength of stripe order. And also, hydrostatic pressure is known to destroy the stripe order. In the static pressure, we found the enhancement of the Nernst signal below superconducting fluctuation temperature Tf~60K. This indicates that the suppression of the stripe strength by applying pressure lead to the enhancement of the superconducting fluctuation. On the other hand, upturn of Nernst signal around 150K could consider to the temperature where fluctuation of the stripe order develops.