Quantum information technologies have attracted much attention in recent years. Advanced fabrication technologies have
made it possible to develop quantum architectures, such as trapped ions, color-defects in crystals (nitrogen-vacancy in
diamond), and Rydberg atoms, where quantum information applications can be implemented. At the heart of this growing
field stands quantum coherence.
In physics, coherence is maintained as long as waves preserve their relative phase, thus enabling the interference phenomenon. The same applies to quantum coherence, which is maintained when the quantum superposition (phase and amplitude) is kept stable. Quantum coherence is at the heart of quantum information technology. The latter can only be realised as long as quantum oherence is preserved. In fact, as quantum applications increase in complexity, coherence time needs to be extended. In a similar manner, longer coherence times reveal higher performance and higher quantum operation fidelity, which is important for ealizations of interesting quantum applications, varying from quantum gates for quantum computation, through quantum simulation of classical intractable systems, to quantum sensing schemes for medical applications.
Noise, leakage and decay channels constitute the main sources for decoherence, which limit the fidelity of the desired quantum operations. In this project my main goal is to theoretically investigate refocusing schemes to maintain coherence in the quantum systems mentioned above, while realizing different quantum applications:
