Quantum Information Processing (QIP) control in hybrid systems

In collaboration with experimentalists (Schmiedmayer, TU Vienna), we investigate the possibilities of quantum information processing transfer and storage in hybrid systems comprised of diverse blocks integrated on chips: superconducting (SC) qubits coupled via a microwave resonator to ensembles of ultra-cold atoms or NV-center spins. Strong coupling between these blocks is mediated by the microwave transmission-line resonator that interacts near- resonantly with the atoms or spins, either via a magnetic-dipole transition or by a Raman process, via their optically excited states. Such hybrid devices allow us to benefit from the advantages of each block and compensate for their disadvantages. Specifically, the SC qubits can rapidly implement quantum logic gates, but are “noisy” (prone to decoherence) while collective metastable states of the atomic or spin ensemble are “quiet” (protected from decoherence) and thus can be employed for long-term storage of quantum information. To improve the overall performance (fidelity) of such devices we propose dynamical control to optimize quantum state transfer from a “noisy” (write-in) qubit to its “quiet” counterpart (storage ensemble). 
Significant improvements of the overall fidelity of hybrid devices are expected under realistic conditions. In particular, hybrid devices may allow higher fidelity of storage than high-Q cavities.

Bath-mediated transfer of quantum information
The ability to transfer an unknown quantum state between nodes where the quantum information (QI) can be reliably stored and/ or processed is at the heart of QI processing and communication schemes. Since practically any medium connecting distant nodes corrupts the QI, one commonly resorts to probabilistic quantum repeaters, effected by conditional measurements: only the desired outcomes are kept while the undesired outcomes are discarded. Such protocols are severely constrained by high qubit-overhead and long average duration of successful QI transfer. It is clearly desirable to resort to deterministic protocols whenever possible. Here we advocate the possibility of such protocols, whose high success rate relies on dynamical control that is optimally adapted to the medium.

Publications:

Kurizki, G; Bertet, P; Kubo, Y; Molmer, K; Petrosyan, D; Rabl, P; Schmiedmayer, J (2015).Quantum Technologies With Hybrid Systems.  Proceedings of the National Academy of Sciences of the United States of America. 112:3866-3873

Zwick, A; Alvarez, Ga; Bensky, G; Kurizki, G (2014). Optimized Dynamical Control of State Transfer Through Noisy Spin Chains.  New Journal of Physics. 16

Shahmoon, E; Kurizki, G (2014). Nonlinear Theory of Laser-Induced Dipolar Interactions in Arbitrary Geometry.  Physical Review A. 89

Shahmoon, E; Mazets, I; Kurizki, G (2014). Non-Additivity in Laser-Illuminated Many-Atom Systems.  Optics Letters. 39:3674-3677

Shahmoon, E; Kurizki, G (2013). Nonradiative Interaction and Entanglement Between Distant Atoms.  Physical Review A. 87

Gordon, G; Mazets, Ie; Kurizki, G (2013). Quantum Particle Localization by Frequent Coherent Monitoring.  Physical Review A. 87

Bensky, G; Petrosyan, D; Majer, J; Schmiedmayer, J; Kurizki, G (2012). Optimizing Inhomogeneous Spin Ensembles For Quantum Memory.  Physical Review A. 86

Davidson, N; Almog, I; Sagi, Y; Gordon, G; Bensky, G; Kurizki, G (2012). Measurement of the System-Environment Coupling and Its Relation to Dynamical Decoupling.  2012 Conference on Lasers and Electro-Optics (Cleo)

Bretschneider, Co; Alvarez, Ga; Kurizki, G; Frydman, L (2012). Controlling Spin-Spin Network Dynamics by Repeated Projective Measurements.  Physical Review Letters. 108

Bensky, G; Amsuss, R; Majer, J; Petrosyan, D; Schmiedmayer, J; Kurizki, G (2011).Controlling Quantum Information Processing in Hybrid Systems on Chips.  Quantum Information Processing. 10:1037-1060

Bar-Gill, N; Rao, Ddb; Kurizki, G (2011). Creating Nonclassical States of Bose-Einstein Condensates by Dephasing Collisions.  Physical Review Letters. 107

Shahmoon, E; Kurizki, G; Fleischhauer, M; Petrosyan, D (2011). Strongly Interacting Photons in Hollow-Core Waveguides.  Physical Review A. 83

Gordon, G; Kurizki, G (2011). Scalability of Decoherence Control in Entangled Systems. Physical Review A. 83

Escher, Bm; Bensky, G; Clausen, J; Kurizki, G (2011). Optimized Control of Quantum State Transfer from Noisy to Quiet Qubits.  Journal of Physics b-Atomic Molecular and Optical Physics. 44

Rao, Ddb; Bar-Gill, N; Kurizki, G (2011). Generation of Macroscopic Superpositions of Quantum States by Linear Coupling to a Bath.  Physical Review Letters. 106

Almog, I; Sagi, Y; Gordon, G; Bensky, G; Kurizki, G; Davidson, N (2011). Direct Measurement of the System-Environment Coupling as a Tool For Understanding Decoherence and Dynamical Decoupling.  Journal of Physics b-Atomic Molecular and Optical Physics. 4

Rao, Ddb; Kurizki, G (2011). From Zeno to Anti-Zeno Regime: Decoherence-Control Dependence on the Quantum Statistics of the Bath.  Physical Review A. 83

Clausen, J; Bensky, G; Kurizki, G (2010). Bath-Optimized Minimal-Energy Protection of Quantum Operations from Decoherence.  Physical Review Letters. 104

Erez, N; Gordon, G; Nest, M; Kurizki, G (2008). Thermodynamic Control by Frequent Quantum Measurements.  Nature. 452:724-727

Gordon, G; Kurizki, G; Lidar, Da (2008). Optimal Dynamical Decoherence Control of a Qubit.  Physical Review Letters. 101