Applications of Graph Spectra in Quantum Physics
Dynamics of entanglement between a quantum dot spin qubit and a photon qubit inside a semiconductor high-Q nanocavity.
Entanglement of Grassmannian coherent states for multi-partite -level systems.
From random telegraph to Gaussian stochastic noises: decoherence and spectral diffusion in a semiconductor quantum dot.
Generating series and asymptotics of classical spin networks
We study classical spin networks with group SU. In the first part, using Gaussian integrals, we compute their generating series in the case where the edges are equipped with holonomies; this generalizes Westbury’s formula. In the second part, we use an integral formula for the square of the spin network and perform stationary phase approximation under some non-degeneracy hypothesis. This gives a precise asymptotic behavior when the labels are rescaled by a constant going to infinity.
On the cardinality of complex matrix scalings
We disprove a conjecture made by Rajesh Pereira and Joanna Boneng regarding the upper bound on the number of doubly quasi-stochastic scalings of an n × n positive definite matrix. In doing so, we arrive at the true upper bound for 3 × 3 real matrices, and demonstrate that there is no such bound when n ≥ 4.
Partial Bell-state analysis with parametric down conversion in the Wigner function formalism.
Quantum entanglement: separability, measure, fidelity of teleportation, and distillation.
Resonant perturbation theory of decoherence and relaxation of quantum bits.
Simulation of equatorial von Neumann measurements on GHZ states using nonlocal resources.
The theory and applications of complex matrix scalings
We generalize the theory of positive diagonal scalings of real positive definite matrices to complex diagonal scalings of complex positive definite matrices. A matrix A is a diagonal scaling of a positive definite matrix M if there exists an invertible complex diagonal matrix D such that A = D*MD and where every row and every column of A sums to one. We look at some of the key properties of complex diagonal scalings and we conjecture that every n by n positive definite matrix has at most 2n−1 scalings...