Avoided Quantum Tricritical Point and Emergence of a Canted Magnetic Phase in LaCr_{1-x}Fe_{x}Sb_{3}.

ABSTRACT

New phases or new phenomena are often observed near-zero temperature phase transitions. These new effects represent nature's way of avoiding quantum critical phase transitions. Here, we look at the quantum tricritical point (QTCP), the special case where two transitions are driven to zero temperature at the same time. Unlike the case of quantum critical points, the avoidance of quantum tricritical points has yet to be demonstrated. Using chemical substitution and a magnetic field, we drive LaCrSb_{3} toward a quantum tricritical point. For the first time near a QTCP, we observe the emergence of a new magnetic phase and the avoidance of the QTCP via a first order phase transition.