اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدQuantum direct communication protocols using discrete-time quantum walk
79
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
The unique features of quantum walk, such as the possibility of the walker to be in superposition ofthe position space and get entangled with the position space, provides inherent advantages that canbe captured to design highly secure quantum communication protocols. Here we propose two quan-tum direct communication protocols, a Quantum Secure Direct Communication (QSDC) protocoland a Controlled Quantum Dialogue (CQD) protocol using discrete-time quantum walk on a cycle.The proposed protocols are unconditionally secure against various attacks such as the intercept-resend attack, the denial of service attack, and the man-in-the-middle attack. Additionally, theproposed CQD protocol is shown to be unconditionally secure against an untrusted service providerand both the protocols are shown more secure against the intercept resend attack as compared tothe qubit based LM05/DL04 protocol.
قيم البحث
اقرأ أيضاً
We study the quantum walk search algorithm of Shenvi, Kempe and Whaley [PRA 67 052307 (2003)] on data structures of one to two spatial dimensions, on which the algorithm is thought to be less efficient than in three or more spatial dimensions. Our ai
m is to understand why the quantum algorithm is dimension dependent whereas the best classical algorithm is not, and to show in more detail how the efficiency of the quantum algorithm varies with spatial dimension or accessibility of the data. Our numerical results agree with the expected scaling in 2D of $O(sqrt{N log N})$, and show how the prefactors display significant dependence on both the degree and symmetry of the graph. Specifically, we see, as expected, the prefactor of the time complexity dropping as the degree (connectivity) of the structure is increased.
Quantum walk has been regarded as a primitive to universal quantum computation. By using the operations required to describe the single particle discrete-time quantum walk on a position space we demonstrate the realization of the universal set of qua
ntum gates on two- and three-qubit systems. The idea is to utilize the effective Hilbert space of the single qubit and the position space on which it evolves in order to realize multi-qubit states and universal set of quantum gates on them. Realization of many non-trivial gates and engineering arbitrary states is simpler in the proposed quantum walk model when compared to the circuit based model of computation. We will also discuss the scalability of the model and some propositions for using lesser number of qubits in realizing larger qubit systems.
Here we present neutrino oscillation in the frame-work of quantum walks. Starting from a one spatial dimensional discrete-time quantum walk we present a scheme of evolutions that will simulate neutrino oscillation. The set of quantum walk parameters
which is required to reproduce the oscillation probability profile obtained in both, long range and short range neutrino experiment is explicitly presented. Our scheme to simulate three-generation neutrino oscillation from quantum walk evolution operators can be physically realized in any low energy experimental set-up with access to control a single six-level system, a multiparticle three-qubit or a qubit-qutrit system. We also present the entanglement between spins and position space, during neutrino propagation that will quantify the wave function delocalization around instantaneous average position of the neutrino. This work will contribute towards understanding neutrino oscillation in the framework of the quantum information perspective.
Recently, Hwang et al. [Eur. Phys. J. D. 61, 785 (2011)] and Yuan et al. [Int. J. Theo. Phys. 50, 2403 (2011)] have proposed two efficient protocols of secure quantum communication using 3-qubit and 4-qubit symmetric W state respectively. These two d
ense coding based protocols are generalized and their efficiencies are considerably improved. Simple bounds on the qubit efficiency of deterministic secure quantum communication (DSQC) and quantum secure direct communication (QSDC) protocols are obtained and it is shown that dense coding is not essential for designing of maximally efficient DSQC and QSDC protocols. This fact is used to design maximally efficient protocols of DSQC and QSDC using 3-qubit and 4-qubit W states.
Quantum percolation describes the problem of a quantum particle moving through a disordered system. While certain similarities to classical percolation exist, the quantum case has additional complexity due to the possibility of Anderson localisation.
Here, we consider a directed discrete-time quantum walk as a model to study quantum percolation of a two-state particle on a two-dimensional lattice. Using numerical analysis we determine the fraction of connected edges required (transition point) in the lattice for the two-state particle to percolate with finite (non-zero) probability for three fundamental lattice geometries, finite square lattice, honeycomb lattice, and nanotube structure and show that it tends towards unity for increasing lattice sizes. To support the numerical results we also use a continuum approximation to analytically derive the expression for the percolation probability for the case of the square lattice and show that it agrees with the numerically obtained results for the discrete case. Beyond the fundamental interest to understand the dynamics of a two-state particle on a lattice (network) with disconnected vertices, our study has the potential to shed light on the transport dynamics in various quantum condensed matter systems and the construction of quantum information processing and communication protocols.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
