# Anisotropy of the Spin Density Wave Onset for (TMTSF)_2PF_6 in Magnetic Field

## TL;DR

This study investigates how magnetic fields affect the spin density wave transition temperature in (TMTSF)_2PF_6, revealing orientation-dependent behaviors consistent with theoretical models.

## Contribution

The paper provides experimental measurements of T_SDW under various magnetic field orientations and pressures, confirming theoretical predictions about anisotropic effects.

## Key findings

- Quadratic field dependence of T_SDW for B||c*
- No shift in T_SDW for B||a and B||b' orientations
- Results align with existing theoretical models

## Abstract

In order to study the spin density wave transition temperature (T_SDW) in (TMTSF)_2PF_6 as a function of magnetic field, we measured the magnetoresistance R_zz in fields up to 19 T. Measurements were performed for three field orientations B||a, b' and c* at ambient pressure and at P = 5 kbar, that is nearly the critical pressure. For B||c* orientation we observed quadratic field dependence of T_SDW in agreement with theory and with previous experiments. For B||b' and B||a orientations we have found no shift in T_SDW within 0.05 K, both at P=0 and P=5 kbar. This result is also consistent with theoretical predictions.