Experimental Observation of a Topological Phase in the Maximally Entangled State of a Pair of Qubits

Abstract

Quantum mechanical phase factors can be related to dynamical effects or to the geometrical properties of a trajectory in a given space - either parameter space or Hilbert space. Here, we experimentally investigate a quantum mechanical phase factor that reflects the topology of the SO(3) group: since rotations by $\pi$ around antiparallel axes are identical, this space is doubly connected. Using pairs of nuclear spins in a maximally entangled state, we subject one of the spins to a cyclic evolution. If the corresponding trajectory in SO(3) can be smoothly deformed to a point, the quantum state at the end of the trajectory is identical to the initial state. For all other trajectories the quantum state changes sign.

References in corpus (4)

• Topological Computation without Braiding
• An experimental observation of geometric phases for mixed states using NMR interferometry
• Phase Dynamics of Two Entangled Qubits
• Quantum information processing using strongly-dipolar coupled nuclear spins

Cited by in corpus (10)

• A Family of Non-Abelian Kitaev Models on a Lattice: Topological Confinement and Condensation
• Quantum Computing with NMR
• Topological phases and multiqubit entanglement
• Geometry of quantum evolution in a nonequilibrium environment
• Experimental observation of fractional topological phases with photonic qudits
• Controlling NMR spin systems for quantum computation
• Non-Markovian dynamics of mixed-state geometric phase of dissipative qubits
• Time optimal control based on classification of quantum gates
• Rescaling interactions for quantum control
• Non Abelian structures and the geometric phase of entangled qudits