Kavita Dorai

Implementing quantum-logic operations, pseudopure states, and the Deutsch-Jozsa algorithm using noncommuting selective pulses in NMR

We demonstrate experimentally the usefulness of selective pulses in NMR to perform quantum computation.Three different techniques based on selective pulse excitations have been proposed to prepare a spin system in a pseudopure state. We describe the design of ‘‘portmanteau’’ gates using the selective manipulation of level populations. A selective pulse implementation of the Deutsch-Jozsa algorithm for two and three-qubit quantum computers is demonstrated.

Implementation of a Deutsch-like quantum algorithm utilizing entanglement at the two-qubit level on an NMR quantum-information processor

We describe the NMR implementation of a recently proposed quantum algorithm involving quantum entanglement at the level of two qubits. The algorithm solves a generalization of the Deutsch problem, and distinguishes between even and odd functions using fewer function calls than is possible classically. The manipulation of entangled states of the two qubits is essential here, unlike the Deutsch-Jozsa algorithm and Grover’s search algorithm for two bits.

Fluorine chemical shift tensors in substituted fluorobenzenes using cross correlations in NMR relaxation

The effect of cross correlations between the chemical shift anisotropy of fluorine and its dipolar interaction with nearby protons has been investigated via multi-spin longitudinal relaxation studies in fluorinated benzenes. Experiments have been performed on four different fluorinated benzenes. Significant variations in the value/orientation of the chemical shift anisotropy tensors of fluorine have been observed as a function of substitution.

Experimental construction of generic three-qubit states and their reconstruction from two-party reduced states on an NMR quantum information processor

We experimentally explore the state space of three qubits on an NMR quantum information processor. We construct a scheme to experimentally realize a canonical form for general three-qubit states up to single-qubit unitaries. This form involves a non-trivial combination of GHZ and W-type maximally entangled states of three qubits. The general circuit that we have constructed for the generic state reduces to those for GHZ and W states as special cases. The experimental construction of a generic state is carried out for a nontrivial set of parameters and the good fidelity of preparation is confirmed by complete state tomography. The GHZ and W-states are constructed as special cases of the general experimental scheme. Further, we experimentally demonstrate a curious fact about three-qubit states, where for almost all pure states, the two-qubit reduced states can be used to reconstruct the full three-qubit state. For the case of a generic state and for the W-state, we demonstrate this method of reconstruction by comparing it with the directly tomographed three-qubit state.

Experimental construction of aWsuperposition state and its equivalence to the Greenberger-Horne-Zeilinger state under local filtration

We experimentally construct a novel three-qubit entangled W-superposition (

Determining the parity of a permutation using an experimental NMR qutrit

\rm W \bar{\rm W}

Multiple-spin coherence transfer in linear Ising spin chains and beyond: numerically-optimized pulses and experiments

) state on an NMR quantum information processor. We give a measurement-based filtration protocol for the invertible local operation (ILO) that converts the

Resolving overlaps in diffusion encoded spectra using band-selective pulses in a 3D BEST-DOSY experiment

\rm W \bar{\rm W}

Functional Dynamics in Replication Protein A DNA Binding and Protein Recruitment Domains

state to the GHZ state, using a register of three ancilla qubits. Further we implement an experimental protocol to reconstruct full information about the three-party

Constructing valid density matrices on an NMR quantum information processor via maximum likelihood estimation

\rm W \bar{\rm W}