Generation and Detection of Quantum Correlations and Entanglement on a Spin-Based Quantum Information Processor

Abstract

This thesis focuses on the experimental creation and detection of a variety of quantum correlations using nuclear magnetic resonance hardware. Quantum entanglement, being most common and counter-intuitive, is one of the main type considered in this thesis. Quantum correlations play a major role in achieving, the much talked, computational speedup. Creation and detection of such correlations experimentally is a major thrust area in experimental quantum information processing field. Main goals of the studies undertaken in this thesis were to come up with strategies to detect the entanglement in a 'state-independent' way and with low experimental resources. The core of all the detection protocols is based on our own developed method which enables us to measure any observable with high accuracy. The experimental protocol has been successfully implemented to detect the entanglement of random two-qubit pure states. Further, the schemes for the experimental detection as well as classification of generic and general three-qubit pure states have also been devised and implemented successfully. Quantum correlation possessed by mixed and$/$or separable states e.g. non-classical, bound-entanglement and of non-local nature were also investigated. In all the investigations, the results were verified by one or more alternative ways e.g. full quantum state tomography.

PhD Thesis, Indian Institute of Science Education and Research Mohali (2019), 143 pages, 26 figures, 9 tables, 7 chapters

References in corpus (24)

• Entanglement detection
• A convergent hierarchy of semidefinite programs characterizing the set of quantum correlations
• Bounding the set of quantum correlations
• Detecting Genuine Multipartite Entanglement with Two Local Measurements
• Taming multiparticle entanglement
• Quantifying Entanglement with Witness Operators
• Benchmarking quantum control methods on a 12-qubit system
• Entanglement criteria based on local uncertainty relations are strictly stronger than the computable cross norm criterion
• Experimental bound entanglement in a four-photon state
• Majorization criterion for distillability of a bipartite quantum state
• Optimal two-qubit tomography based on local and global measurements: Maximal robustness against errors as described by condition numbers
• Bound entanglement provides convertibility of pure entangled states
• Class of PPT bound entangled states associated to almost any set of pure entangled states
• Environment assisted entanglement enhancement
• Nonclassical correlation in a multipartite quantum system: two measures and evaluation
• Experimentally implementable criteria revealing substructures of genuine multipartite entanglement
• Thermal Equilibrium as an Initial State for Quantum Computation by NMR
• Accessible nonlinear entanglement witnesses
• Invariant Quantum Discord in Qubit-Qutrit Systems under Local Dephasing
• Estimating Franck-Condon factors using an NMR quantum processor
• Projective measurement in nuclear magnetic resonance
• Quantum to classical transition and entanglement sudden death in Gaussian states under local heat bath dynamics
• Simulating Concordant Computations
• Degree of entanglement for qubit-qutrit state