2.1k citations · 35.5k across the 437 of their papers we have counts for
14 papers · 2 filters
Infinite qubit rings with maximal nearest neighbor entanglement: the Bethe ansatz solution
U. V. Poulsen, T. Meyer, D. Bruss +1
We search for translationally invariant states of qubits on a ring that maximize the nearest neighbor entanglement. This problem was initially studied by O'Connor and Wootters [Phy…
Capacities of noiseless quantum channels for massive indistinguishable particles: Bosons vs. fermions
Aditi Sen De, Ujjwal Sen, Bartosz Gromek +2
We consider information transmission through a noiseless quantum channel, where the information is encoded into massive indistinguishable particles: bosons or fermions. We study th…
The separability versus entanglement problem
Aditi Sen De, Ujjwal Sen, Maciej Lewenstein +1
We review the problem of discriminating entangled states from separable states for bipartite systems. We formally define what entangled states are, present some important criteria…
Disordered complex systems using cold gases and trapped ions
Aditi Sen De, Ujjwal Sen, Maciej Lewenstein +3
We report our research on disordered complex systems using cold gases and trapped ions, and address the possibility of using complex systems for quantum information processing. Two…
Fermi-Dirac statistics and the number theory
A. Kubasiak, J. Korbicz, J. Zakrzewski +1
We relate the Fermi-Dirac statistics of an ideal Fermi gas in a harmonic trap to partitions of given integers into distinct parts, studied in number theory. Using methods of quantu…
Quantum Information Processing in Disordered and Complex Quantum Systems
Aditi Sen De, Ujjwal Sen, Veronica Ahufinger +3
We investigate quantum information processing and manipulations in disordered systems of ultracold atoms and trapped ions. First, we demonstrate generation of entanglement and loca…
Dense coding with multipartite quantum states
Dagmar Bruss, Giacomo Mauro D'Ariano, Maciej Lewenstein +3
We consider generalisations of the dense coding protocol with an arbitrary number of senders and either one or two receivers, sharing a multiparty quantum state, and using a noisel…
Distillation Protocols that Involve Local Distinguishing: Composing Upper and Lower Bounds on Locally Accessible Information
Aditi Sen De, Ujjwal Sen, Maciej Lewenstein
We find a universal lower bound on locally accessible information for arbitrary bipartite quantum ensembles, when one of the parties is two-dimensional. In higher dimensions and in…
Capacities of Quantum Channels for Massive Bosons and Fermions
Aditi Sen De, Ujjwal Sen, Bartosz Gromek +2
We consider the capacity of classical information transfer for noiseless quantum channels carrying a finite average number of massive bosons and fermions. The maximum capacity is a…
Dynamical phase transitions and temperature induced quantum correlations in an infinite spin chain
Aditi Sen De, Ujjwal Sen, Maciej Lewenstein
We study the dynamics of entanglement in the infinite asymmetric XY spin chain, in an applied transverse field. The system is prepared in a thermal equilibrium state (ground state…
Relations between Entanglement Witnesses and Bell Inequalities
P. Hyllus, O. Guehne, D. Bruss +1
Bell inequalities, considered within quantum mechanics, can be regarded as non-optimal witness operators. We discuss the relationship between such Bell witnesses and general entang…
Spin squeezing inequalities and entanglement of qubit states
J. Korbicz, J. I. Cirac, M. Lewenstein
We derive spin squeezing inequalities that generalize the concept of the spin squeezing parameter and provide necessary and sufficient conditions for genuine 2-, or 3- qubit entang…
One- and two-dimensional quantum walks in arrays of optical traps
K. Eckert, J. Mompart, G. Birkl +1
We propose a novel implementation of discrete time quantum walks for a neutral atom in an array of optical microtraps or an optical lattice. We analyze a one-dimensional walk in po…
Usefulness of classical communication for local cloning of entangled states
Rafal Demkowicz-Dobrzanski, Maciej Lewenstein, Aditi Sen De +2
We solve the problem of the optimal cloning of pure entangled two-qubit states with a fixed degree of entanglement using local operations and classical communication. We show, that…