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Biao-Liang Ye

Publications and source records attributed to Biao-Liang Ye.

14 recordsLinked to original sources

Bell-Mermin-Klyshko Inequalities and One-way Information Deficit of Dirac Fields in Noninertial Frames

We investigate the Bell-Mermin-Klyshko inequalities and the one-way information deficit of Dirac fields in noninertial frames, where the quantum correlations are shared between inertial and accelerated observers due to the Unruh effect. We derive partial analytical results for specific quantum states using the one-way information deficit. Additionally, we present numerical results for the Bell-Mermin-Klyshko inequalities. The study reveals the presence of Bell nonlocality and the significance of the one-way information deficit in relativistic quantum information.

quant-ph

Shortcuts to adiabatic state transfer in time-modulated two-level non-Hermitian systems

Nontrivial spectral properties of non-Hermitian systems can give rise to intriguing effects that lack counterparts in Hermitian systems. For instance, when dynamically varying system parameters along a path enclosing an exceptional point (EP), chiral mode conversion occurs. A recent study [Phys. Rev. Lett. 133, 113802 (2024)] demonstrates the achievability of pure adiabatic state transfer by specifically selecting a trajectory in the system parameter space where the corresponding evolution operator exhibits a real spectrum while winding around an EP. However, the intended adiabatic state transfer becomes fragile when taking into account the effect of the nonadiabatic transition. In this work, we propose a scheme for achieving robust and rapid adiabatic state transfer in time-modulated two-level non-Hermitian systems by appropriately modulating system Hamiltonian and time-evolution trajectory. Numerical simulations confirm that complete adiabatic transfer can always be achieved even under nonadiabatic conditions after one period for different initialized adiabatic states, and the scheme remains insensitive to moderate fluctuations in control parameters. Therefore, this scheme offers alternative approaches for quantum-state engineering in non-Hermitian systems.

quant-ph

Entropic uncertainty relations and quantum Fisher information of top quarks in a large hadron collider

We employ the entropic uncertainty relations and the quantum Fisher information to explore the formation of quark $t\bar{t}$ pairs at a large hadron collider through the combination of $q\bar{q}$ pair and $gg$ pair initiated processes. A comprehensive analysis has been undertaken on the procedure of quark and gluon channel mixing in the production of top quark pairs $t\bar{t}$, encompassing the tightness of the entropic uncertainty inequalities and the maximum quantum Fisher information of the system.

hep-ph

Steered quantum coherence and quantum Fisher information in spin-chain system

In this paper, we investigate steered quantum coherence, i.e., the $l_1$ norm of steered coherence and the relative entropy of steered coherence, and the quantum Fisher information in the Gibbs state of two-qubit $XXZ$ systems. Their variations with respect to the temperature, external magnetic field, and interaction intensities are analyzed both analytically and numerically in detail. The similar behaviors among these three quantum measures in the $XXZ$ model are presented.

quant-ph

Quantum Discord for multiqubit Systems

We evaluate analytically the quantum discord for a large family of multiqubit states. It is interesting to note that the quantum discord of three-qubits and five-qubits is the same, as is the quantum discord of two-qubits and six-qubits. We discover that the quantum discord of this family states can be concluded into three categories. The level surfaces of the quantum discord in the three categories is shown through images. Furthermore, we investigated the dynamic behavior of quantum discord under decoherence. For the odd partite systems, we prove the frozen phenomenon of quantum discord doesn't exist under the phase flip channel, while it can be found in the even partite systems.

quant-ph

Optimal approximations of available states and a triple uncertainty relation

We investigate the optimal convex approximation of the quantum state with respect to a set of available states. By isometric transformation, we have presented the general mathematical model and its solutions together with a triple uncertainty equality relation. Meanwhile, we show a concise inequality criterion for decomposing qubit mixed states. The new results include previous ones as special cases. Our model and method may be applied to solve similar problems in high-dimensional and multipartite scenarios

quant-ph

Quantum Fisher information and coherence in one-dimensional $XY$ spin models with Dzyaloshinsky-Moriya interactions

We investigate quantum phase transitions in $XY$ spin models using Dzyaloshinsky-Moriya (DM) interactions. We identify the quantum critical points via quantum Fisher information and quantum coherence, finding that higher DM couplings suppress quantum phase transitions. However, quantum coherence (characterized by the $l_1$-norm and relative entropy) decreases as the DM coupling increases. Herein, we present both analytical and numerical results.

quant-ph

Complete Optimal Convex Approximations of Qubit States under $B_2$ Distance

We consider the optimal approximation of arbitrary qubit states with respect to an available states consisting the eigenstates of two of three Pauli matrices, the $B_2$-distance of an arbitrary target state. Both the analytical formulae of the $B_2$-distance and the corresponding complete optimal decompositions are obtained. The tradeoff relations for both the sum and the squared sum of the $B_2$-distances have been analytically and numerically investigated.

quant-ph

Quantum correlations in critical $XXZ$ system and LMG model

We investigate the quantum phase transitions for the $XXZ$ spin-1/2 chains via the quantum correlations between the nearest and next to nearest neighbor spins characterized by negativity, information deficit, trace distance discord and local quantum uncertainty. It is shown that all these correlations exhibit the quantum phase transitions at $Δ=-1$. However, only information deficit and local quantum uncertainty can demonstrate quantum phase transitions at $Δ=1$. The analytical and numerical behaviors of the quantum correlations for the $XXZ$ system are presented. We also consider quantum correlations in the Hartree-Fock ground state of the Lipkin-Meshkov-Glick (LMG) model.

quant-ph

One-way quantum deficit and quantum coherence in the anisotropic $XY$ chain

In this study, we investigate pairwise non-classical correlations measured using a one-way quantum deficit as well as quantum coherence in the $XY$ spin-1/2 chain in a transverse magnetic field for both zero and finite temperatures. The analytical and numerical results of our investigations are presented. In the case when the temperature is zero, it is shown that the one-way quantum deficit can characterize quantum phase transitions as well as quantum coherence. We find that these measures have a clear critical point at $λ=1$. When $λ\le1$, the one-way quantum deficit has an analytical expression that coincides with the relative entropy of coherence. We also study an $XX$ model and an Ising chain at the finite temperatures.

quant-ph

One-way quantum deficit for $2\otimes d$ systems

We investigate one-way quantum deficit for $2\otimes d$ systems. Analytical expressions of one-way quantum deficit under both von Neumann measurement and weak measurement are presented. As an illustration, qubit-qutrit systems are studied in detail. It is shown that there exists non-zero one-way quantum deficit even quantum entanglement vanishes. Moreover, one-way quantum deficit via weak measurement turns out to be weaker than that via von Neumann measurement. The dynamics of entanglement and one-way quantum deficit under dephasing channels is also investigated.

quant-ph

One-way Quantum Deficit and Decoherence for Two-qubit $X$ States

We study one-way quantum deficit of two-qubit $X$ states systematically from analytical derivations. An effective approach to compute one-way quantum deficit of two-qubit $X$ states has been provided. Analytical results are presented as for detailed examples. Moreover, we demonstrate the decoherence of one-way quantum deficit under phase damping channel.

quant-ph

A note on one-way quantum deficit and quantum discord

One-way quantum deficit and quantum discord are two important measures of quantum correlations. We revisit the relationship between them in two-qubit systems. We investigate the conditions that both one-way quantum deficit and quantum discord have the same optimal measurement ensembles, and demonstrate that one-way quantum deficit can be derived from the quantum discord for a class of X states. Moreover, we give an explicit relation between one-way quantum deficit and entanglement of formation. We show that under phase damping channel both one-way quantum deficit and quantum discord evolve exactly in the same way for four parameters X states. Some examples are presented in details.

quant-ph