306 citations · 1.7k across the 29 of their papers we have counts for
29 papers
CP-preserving channels
Indu Bala, Sourav Das, Swapan Rana
Completely positive (CP) matrices are ubiquitous in modern science and technology with applications in optimization, graph theory, and quantum entanglement. Recently, Johnston \emp…
Extremal Marginal States of Maximal Rank in
Indu Bala, Swapan Rana
We study the extreme points of the convex set of bipartite quantum states with fixed marginals and . We construct extreme points in di…
Resource Theory of Imaginarity: New Distributed Scenarios
Kang-Da Wu, Tulja Varun Kondra, Carlo Maria Scandolo +5
The resource theory of imaginarity studies the operational value of imaginary parts in quantum states, operations, and measurements. Here we introduce and study the distillation an…
Creating and destroying coherence with quantum channels
Masaya Takahashi, Swapan Rana, Alexander Streltsov
The emerging quantum technologies rely on our ability to establish and control quantum systems in nonclassical states, exhibiting entanglement and quantum coherence. It is thus cru…
Resource theory of imaginarity: Quantification and state conversion
Kang-Da Wu, Tulja Varun Kondra, Swapan Rana +5
Complex numbers are widely used in both classical and quantum physics, and are indispensable components for describing quantum systems and their dynamical behavior. Recently, the r…
Operational Resource Theory of Imaginarity
Kang-Da Wu, Tulja Varun Kondra, Swapan Rana +5
Wave-particle duality is one of the basic features of quantum mechanics, giving rise to the use of complex numbers in describing states of quantum systems, their dynamics, and inte…
Entanglement negativity as a universal non-Markovianity witness
Jan Kolodynski, Swapan Rana, Alexander Streltsov
In order to engineer an open quantum system and its evolution, it is essential to identify and control the memory effects. These are formally attributed to the non-Markovianity of…
Optimal decomposition of incoherent qubit channel
Swapan Rana, Maciej Lewenstein
We show that any incoherent qubit channel could be decomposed into four incoherent Kraus operators. The proof consists in showing existence of four incoherent Kraus operators by de…
Activation of entanglement from quantum coherence and superposition
Lu-Feng Qiao, Jun Gao, Alexander Streltsov +11
Quantum entanglement and coherence are two fundamental features of nature, arising from the superposition principle of quantum mechanics. While considered as puzzling phenomena in…
Structure of the resource theory of quantum coherence
Alexander Streltsov, Swapan Rana, Paul Boes +1
Quantum coherence is an essential feature of quantum mechanics which is responsible for the departure between classical and quantum world. The recently established resource theory…
Entanglement and Nonlocality in Diagonal Symmetric States of -qubits
Ruben Quesada, Swapan Rana, Anna Sanpera
We analyze entanglement and nonlocal properties of the convex set of symmetric -qubits states which are diagonal in the Dicke basis. First, we demonstrate that within this set,…
Logarithmic coherence: Operational interpretation of -norm coherence
Swapan Rana, Preeti Parashar, Andreas Winter +1
We show that the distillable coherence---which is equal to the relative entropy of coherence---is, up to a constant factor, always bounded by the -norm measure of coherence…
Entanglement and coherence in quantum state merging
A. Streltsov, E. Chitambar, S. Rana +3
Understanding the resource consumption in distributed scenarios is one of the main goals of quantum information theory. A prominent example for such a scenario is the task of quant…
Sufficient separability criteria and linear maps
Maciej Lewenstein, Remigiusz Augusiak, Dariusz Chruściński +2
We study families of positive and completely positive maps acting on a bipartite system (with ). The maps have a property that when appl…
Trace-distance measure of coherence
Swapan Rana, Preeti Parashar, Maciej Lewenstein
We show that trace distance measure of coherence is a strong monotone for all qubit and, so called, states. An expression for the trace distance coherence for all pure states a…
Towards resource theory of coherence in distributed scenarios
Alexander Streltsov, Swapan Rana, Manabendra Nath Bera +1
The search for a simple description of fundamental physical processes is an important part of quantum theory. One example for such an abstraction can be found in the distance lab p…
Assisted distillation of quantum coherence
E. Chitambar, A. Streltsov, S. Rana +3
We introduce and study the task of assisted coherence distillation. This task arises naturally in bipartite systems where both parties work together to generate the maximal possibl…
Maximally discordant separable two qubit states
Swapan Rana, Preeti Parashar
In a recent article S. Gharibian [\href{http://dx.doi.org/10.1103/PhysRevA.86.042106}{Phys. Rev. A {\bf 86}, 042106 (2012)}] has conjectured that no two qubit separable state of ra…
Comment on "Sudden change in quantum discord accompanying the transition from bound to free entanglement"
Swapan Rana, Preeti Parashar
In a recent article [http://dx.doi.org/10.1103/PhysRevA.87.022340, Phys. Rev. A 87, 022340 (2013)], Yan et al have studied geometric discord for a well known class of bound entangl…
Negative eigenvalues of partial transposition of arbitrary bipartite states
Swapan Rana
The partial transposition of a two-qubit state has at most one negative eigenvalue and all the eigenvalues lie in [-1/2,1]. In this Brief Report, we extend this result by Sanpera e…
Comment on "Witnessed entanglement and the geometric measure of quantum discord"
Swapan Rana, Preeti Parashar
In a recent article [Phys. Rev. A 86, 024302 (2012)], the authors have derived some hierarchy relations between geometric discord and entanglement (measured by negativity and its s…
Entanglement is not a lower bound for geometric discord
Swapan Rana, Preeti Parashar
We show that partial transposition of any state can have at most number of negative eigenvalues. This extends a decade old result of case by Sanpe…
Geometric discord and Measurement-induced nonlocality for well known bound entangled states
Swapan Rana, Preeti Parashar
We employ geometric discord and measurement induced nonlocality to quantify non classical correlations of some well-known bipartite bound entangled states, namely the two families…
Tight lower bound on geometric discord of bipartite states
Swapan Rana, Preeti Parashar
We use singular value decomposition to derive a tight lower bound for geometric discord of arbitrary bipartite states. In a single shot this also leads to an upper bound of measure…