The role of quantum symmetries

Wenfang Xie, Bao Cheng-guang

A three-fernion system with their spin aligned is examined to reveal that the quantum mechanical symmetry plays a decisive role in determining microscopic structures.

Valter Moretti

Luka Antonić, Yariv Kafri, Daniel K. Podolsky +1 more

In quantum mechanics, measurements are dynamical processes and thus they should be capable of inducing currents. The symmetries of the Hamiltonian and measurement operator provide an organizing principle for understanding the conditions for such currents to emerge. The central role is played by the inversion and time-reversal symmetries. We classify the distinct behaviors that emerge from single and repeated measurements, with and without coupling to a dissipative bath. While the breaking of inversion symmetry alone is sufficient to generate currents through measurements, the breaking of time-reversal symmetry by the measurement operator leads to a dramatic increase in the magnitude of the currents. We consider the dependence on the measurement rate and find that the current is nonmonotonic. Furthermore, nondegenerate measurements can lead to current loops within the steady state even in the Zeno limit.

Heinz Dietrich Doebner, V. K. Dobrev

Georg Junker

Symmetry is a fundamental concept in science and has played a significant role since the early days of quantum physics [...]

Heinz Dietrich Doebner, Jörg Hennig, W. Lücke +1 more