Associate Professor Scott Parkins

MSc, DPhil (Waikato)

Contact details
Building 303, Room 631
Phone: +64 9 373 7599 ext 86282
Email: s.parkins@auckland.ac.nz

• Theoretical Quantum Optics.
• Quantum Information and Quantum Computation.
• Quantum Chaos.

Quantum State Transfer and Teleportation
Recent experiments trapping single atoms inside high-finesse optical resonators open the door to a host of exciting possibilities in the field of cavity quantum electrodynamics (cavity QED). In particular, schemes can be developed for quantum networks, in which cavity QED systems constitute nodes of the network and quantum information (i.e., quantum states) is "stored" in internal or external degrees of freedom of the trapped atoms. Communication between nodes is mediated by propagating (quantum) light fields, and in this way it is in principle possible to prepare entangled quantum states of atoms at distantly separated locations. Such entangled states can be employed in a variety of quantum communication protocols, such as teleportation. They are also of tremendous interest from the point of view of fundamental quantum mechanics.

Entanglement Engineering of Atomic Systems
The properties of entangled mixed states and schemes for their controlled preparation are presently under vigorous investigation, primarily because of their relevance to understanding the role of purity and entanglement in quantum computation and quantum communication. The purity and degree of entanglement of two-qubit states can be quantified, respectively, by the linear entropy and either the entanglement of formation or the concurrence. Schemes can be developed, using interactions in cavity QED, to prepare states of two atomic qubits with any allowed combination of entropy and concurrence. These schemes can also be generalised to larger collections of atoms, where more complicated entangled states are possible owing to the larger dimensionality of the system. The modeling and characterisation of such multi-atom entangled states is a challenging problem of great significance to the fields of many-body quantum physics and quantum information.

Quantum Chaos in the Atom Optics Kicked Rotor
Ultra cold atoms, confined in magneto-optical traps and subjected to repeated momentum "kicks" from an off-resonant laser field, offer a unique and pristine environment for investigations of certain prototypal systems in the field of quantum chaos (e.g., the kicked rotor). In collaboration with the experimental atom-trapping group at the University of Auckland, theoretical and numerical models of such systems are being developed and studied with the aim of investigating the influence of various forms of coupling to the environment and the precise nature of the transition from quantum localisation of momentum to classical chaotic behaviour that such coupling induces.
 

• AOKI, T., PARKINS, A.S., ALTON, D.J., REGAL, C.A., DAYAN, B., OSTBY, E., VAHALA, K.J., KIMBLE, H.J. 'Efficient routing of single photons by one atom and a microtoroidal cavity', Physical Review Letters, 102, 083601, 2009
• MORRISON, S., PARKINS, A.S. 'Dissipation-driven quantum phase transitions in collective spin systems', Journal of Physics B: Atomic, Molecular & Optical Physics, 41, 195502, 2008
• SADGROVE, M., WIMBERGER, S., PARKINS, S., LEONHARDT, R. 'Scaling law and stability for a noisy quantum system', Physical Review E, 78, 025206, 2008
• MORRISON, S., PARKINS, A.S. 'Collective spin systems in dispersive optical cavity QED: Quantum phase transitions and entanglement', Physical Review A, 77, 043810, 2008
• CHIA, A., PARKINS, A.S. 'Entangled-state cycles of atomic collective-spin states', Physical Review A, 77, 033810, 2008
• DAYAN, B., PARKINS, A.S., AOKI, T., KIMBLE, H.J., OSTBY, E.P., VAHALA, K. 'A photon turnstile dynamically regulated by one atom', Science, 319, 1062, 2008
• MORRISON, S., PARKINS, A.S. 'Dynamical quantum phase transitions in the dissipative Lipkin-Meshkov-Glick model with proposed realization in optical cavity QED', Physical Review Letters, 100, 040403, 2008
• DIMER, F., ESTIENNE, B., PARKINS, A.S., CARMICHAEL, H.J. 'Proposed realization of the Dicke-model quantum phase transition in an optical cavity QED system', Physical Review A, 75, 013804, 2007
• BIRNBAUM, K.M., PARKINS, A.S., KIMBLE, H.J. 'Cavity QED with multiple hyperfine levels', Physical Review A, 74, 063802, 2006
• AOKI, T., DAYAN, B., WILCUT, E., BOWEN, W.P., PARKINS, A.S., KIPPENBERG, T.J., VAHALA, K.J., KIMBLE, H.J. 'Observation of strong coupling between one atom and a monolithic microresonator', Nature, 443, 671, 2006
• GRAHAM, D.J.L., PARKINS, A.S., WATKINS, L.R. 'Ellipsometry with polarisation-entangled photons', Optics Express, 14, 7037, 2006
• GU, M., PARKINS, A.S., CARMICHAEL, H.J. 'Entangled-state cycles from conditional quantum evolution', Physical Review A, 73, 043813, 2006
• PARKINS, A.S., SOLANO, E., CIRAC, J.I. 'Unconditional two-mode squeezing of separated atomic ensembles', Physical Review Letters, 96, 053602, 2006
• S.G. Clark and A.S. Parkins, Entanglement and entropy engineering of atomic two-qubit states. Phys. Rev. Lett. 90 047905 (2003).
• A.J. Daley and A.S. Parkins, Early time diffusion for the quantum kicked rotor with narrow initial momentum distributions. Phys. Rev. E 66 056210 (2002).
• A. Peng and A.S Parkins, Motion-light parametric amplifier and entanglement distributor. Phys. Rev. A 65 062323 (2002).
• S. Rebic, A.S. Parkins, and S.M. Tan, Photon statistics of a single atom intracavity system involving electromagnetically induced transparency. Phys. Rev. A 65 063804 (2002).
• S. Rebic, A.S. Parkins, and S.M. Tan, Polariton analysis of a four-level atom strongly coupled to a cavity mode. Phys. Rev. A 65 043806 (2002).
• A.J. Daley, A.S. Parkins, R. Leonhardt, and S.M. Tan, Diffusion resonances in action space for an atom optics kicked rotor with decoherence. Phys. Rev. E 65 035201(R) (2002).