Temperature-dependent remote control of polarization and coherence intensity with sender’s pure initial state

Abstract

We study the remote creation of the polarization and intensity of the first-order coherence (or coherence intensity) in long spin-1/2 chains with one qubit sender and receiver. Therewith we use a physically motivated initial condition with the pure state of the sender and the thermodynamical equilibrium state of the other nodes. The main part of the creatable region is a one-to-one map of the initial-state (control) parameters, except the small subregion twice covered by the control parameters, which appears owing to the chosen initial state. The polarization and coherence intensity behave differently in the state creation process. In particular, the coherence intensity can not reach any significant value unless the polarization is large in long chains (unlike the short ones), but the opposite is not true. The coherence intensity vanishes with an increase in the chain length, while the polarization (by absolute value) is not sensitive to this parameter. We represent several characteristics of the creatable polarization and coherence intensity and describe their relation to the parameters of the initial state. The link to the eigenvalue-eigenvector parametrization of the receiver's state-space is given.

Transfer of scaled multiple-quantum coherence matrices

“…The problem of a pure state evolution in such a communication line was considered in Ref. [20]; here we remind the nesessary details.…”

“…which is independent on the sender's initial state. It can be shown numerically that condition (20) with f given in (15)…”

“…[16]. Recently, different aspects of state creation in spin-1/2 chains have been considered: the optimization of creatable region via local unitary transformations of sender and extended receiver [17][18][19], the remote manipulation of multi-quantum coherences [20], the creation of particular two-qubit states [21].…”

M-neighbor approximation in one-qubit state transfer along zigzag and alternating spin-1/2 chains

“…We recall that the nearest-neighbor interaction is a very popular model in describing the spin evolution governed by XX, XY and XXZ Hamiltonians [7,8,44,45]. It is remarkable that most papers quoted above are based on the nearest-neighbor interaction [14,16,18,19,23,24,29,31,40,41].…”

Удаленный контроль fквантовыми корреляциями двухкубитного приемника посредством трехкубитного передатчика

“…Создание таких состояний с помощью цепочки спинов является предметом изучения работы [36], в которой эта идея сформулирована для смешанного состояния передатчика в короткой цепочке. Создание состояния, контролируемого чистым состоянием передатчика с односпиновым возбуждением, изучено в работе [37], аналогичная проблема с физически обоснованным начальным состоянием рассмотрена в статье [38]. Следует также отметить, что предлагаемый в настоящей статье алгоритм создания квантовых состояний развивает идею переноса квантовой информации [39]- [41], которая является альтернативой переносу квантового состояния.…”