arXiv subjects

Arpita Maitra

Publications and source records attributed to Arpita Maitra.

24 records · Page 2Linked to original sources

arXiv2015

Eavesdropping in Semiquantum Key Distribution Protocol

In semiquantum key-distribution (Boyer et al.) Alice has the same capability as in BB84 protocol, but Bob can measure and prepare qubits only in $\{|0\rangle, |1\rangle\}$ basis and reflect any other qubit. We study an eavesdropping strategy on this scheme that listens to the channel in both the directions. With the same level of disturbance induced in the channel, Eve can extract more information using our two-way strategy than what can be obtained by the direct application of one-way eavesdropping in BB84.

quant-ph↗

arXiv2013

Efficient quantum algorithm to construct arbitrary Dicke states

In this paper, we study efficient algorithms towards the construction of any arbitrary Dicke state. Our contribution is to use proper symmetric Boolean functions that involve manipulations with Krawtchouk polynomials. Deutsch-Jozsa algorithm, Grover algorithm and the parity measurement technique are stitched together to devise the complete algorithm. Further, motivated by the work of Childs et al (2002), we explore how one can plug the biased Hadamard transformation in our strategy. Our work compares fairly with the results of Childs et al (2002).

quant-ph↗

arXiv2012

Third Party CNOT Attack on MDI QKD

In this letter, we concentrate on the very recently proposed Measurement Device Independent Quantum Key Distribution (MDI QKD) protocol by Lo, Curty and Qi (PRL, 2012). We study how one can suitably present an eavesdropping strategy on MDI QKD, that is in the direction of the fundamental CNOT attack on BB84 protocol, though our approach is quite different. In this strategy, Eve will be able to know expected half of the secret bits communicated between Alice and Bob with certainty (probability 1) without introducing any error. Further, for the remaining bits, where Eve will only be able to predict the bit values as in random guess (with probability 1/2), she will certainly find out whether her interaction induced an error in the secret bits between the communicating parties. Given the asymmetric nature of the CNOT attack, we also introduce Hadamard gates to present a symmetric version. Though our analysis does not refute the security claims in MDI QKD, adapting the CNOT attack in this scenario requires nontrivial approach using entanglement swapping.

quant-ph↗

arXiv2012

Some Possibility and Impossibility Results related to Discrete Fourier type transforms in Quantum Information

Very recently the most general ensemble of qubits are identified using the notion of linearity; any of these qubits gets accepted by a Hadamard gate to generate the equal superposition of the qubit and its orthogonal. Towards more generalization, we investigate the possibility and impossibility results related to Discrete Fourier Transform (DFT) type of operations for a more general set up of qutrits.

quant-ph↗

arXiv2011

On Admissible States of Quantum Fourier Transform

We present a general methodology to obtain the basis of qudits which are admissible to Quantum Fourier Transform (QFT). We first study this method for qubits to characterize the ensemble that works for the Hadamard transformation (QFT for two dimension). In this regard we identify certain incompleteness in the result of Maitra and Parashar (IJQI, 2006). Next we characterize the ensemble of qutrits for which QFT is possible. Further, some theoretical results related to higher dimensions are also discussed.

quant-ph↗

arXiv2005

Hadamard type operations for qubits

We obtain the most general ensemble of qubits, for which it is possible to design a universal Hadamard gate. These states when geometrically represented on the Bloch sphere, give a new trajectory. We further consider some Hadamard `type' of operations and find ensembles of states for which such transformations hold. Unequal superposition of a qubit and its orthogonal complement is also investigated.

quant-ph↗