Improved Stability of Electron Spins in Qubits

Double quantum dot: The three lower and upper trap up to two individual electrons, the spin states of which form the quantum-mechanical information unit. The lateral act as sensors. (Image: University of Basel, Department of Physics) Calculation with electron spins in a quantum computer assumes that the spin states last for a sufficient period of time. Physicists at the University of Basel and the Swiss Nanoscience Institute have now demonstrated that electron exchange in quantum dots fundamentally limits the stability of this information. Control of this exchange process paves the way for further progress in the coherence of the fragile quantum states. The report from the Basel-based researchers appears in the scientific journal Physical Review Letters. The basic idea of a quantum computer is to replace the ones and zeros used in today's bits with quantum states, or qubits.