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Quantum versus classical correlations in Gaussian states.
Quantum discord, a measure of genuinely quantum correlations, is generalized to continuous variable systems. For all two-mode Gaussian states, we calculate analytically the quantum discord and a
Quantum discord and the power of one qubit.
We use quantum discord to characterize the correlations present in the model called deterministic quantum computation with one quantum bit (DQC1), introduced by Knill and Laflamme [Phys. Rev. Lett.
Boson Sampling on a Photonic Chip
A quantum boson-sampling machine (QBSM) is constructed to sample the output distribution resulting from the nonclassical interference of photons in an integrated photonic circuit, a problem thought to be exponentially hard to solve classically.
Highly efficient energy excitation transfer in light-harvesting complexes: The fundamental role of n
This work identifies key mechanisms through which noise such as dephasing, perhaps counter intuitively, may actually aid transport through a dissipative network by opening up additional pathways for excitation transfer.
Noise-assisted energy transfer in quantum networks and light-harvesting complexes
We provide physically intuitive mechanisms for the effect of noise on excitation energy transfer (EET) in networks. Using these mechanisms of dephasing-assisted transport (DAT) in a hybrid basis of
Quantum enhanced multiple phase estimation.
This work identifies quantum probe states that provide an enhancement compared to the best quantum scheme for the estimation of each individual phase separately as well as improvements over classical strategies that provides an advantage in the variance of the estimation over individual quantum estimation schemes that scales as O(d), where d is the number of phases.
Studies on the Role of Entanglement in Mixed-state Quantum Computation
In this thesis, I look at the role of quantum entanglement in mixed-state quantum computation. The model we consider is the DQC1 or `power of one qubit' model. I show that there is minimal bipartite
Quantum-limited metrology with product states
We study the performance of initial product states of n-body systems in generalized quantum metrology protocols that involve estimating an unknown coupling constant in a nonlinear k-body (kn)
A Condition for the Nullity of Quantum Discord
  • A. Datta
  • Physics, Mathematics
  • 27 March 2010
The positivity of quantum discord is shown to be equivalent to the strong subadditivity of von-Neumann entropy. This leads us to a necessary and sufficient condition characterizing the set of states
Entanglement and the power of one qubit
The ``power of one qubit'' refers to a computational model that has access to only one pure bit of quantum information, along with $n$ qubits in the totally mixed state. This model, though not as