Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Molecular Physics

Alternative approach of generating entanglement in quantum dots by spatial phase

Kenji Mishima, Koichi Yamashita

Published Apr 10, 2012• 0 citations
Publisher

Abstract

An alternative method is proposed for generating efficiently the entangled states in semiconductor quantum dots by using the spatial phase. The method does not rely on the frequently used dipole–dipole interaction among the qubits at all. It was found that as a result of breaking the selection rule by the spatial phase it enables one to create the entanglement that can never be realized when closely located identical quantum dots are used as qubit gates. In this paper generation of entanglements in two- and three-qubit systems is investigated. The experimental setup based on our approach is much clearer and simpler than that based on the dipole-dipole interaction.

DOI
10.1080/00268976.2012.668966

Related papers

Novel approach of performing elementary quantum operations using spatial phase

K. Mishima, Michitoshi Hayashi, S. H. Lin

We propose a new idea of generating and controlling quantum coherences among semiconductor quantum dots by using the spatial phase of one single-mode incident laser pulse. Two or three identical quantum dots are employed as qubit gates. Our strategy is to use the spatial phase of the laser pulse at the different positions of the qubits for quantum operations, rather than to utilize dipole-dipole interactions between them. In this work, Hadamard transformation and creation of entanglements in the bipartite and tripartite systems are examined. We predict that with much simpler experimental setup the spatial phase of the laser pulse makes it possible to perform elementary quantum operations that are infeasible by the present-day quantum computer architecture.

•Jul 8, 2004•0 citations

Quantum communication with quantum dot spins

Christoph Simon, Yann‐Michel Niquet, Xavier Caillet +3 more

Single electron spins in quantum dots are attractive for quantum communication because of their expected long coherence times. We propose a method to create entanglement between two remote spins based on the coincident detection of two photons emitted by the dots. Local nodes of two or more qubits can be realized using the dipole-dipole interaction between trions in neighboring dots and spectral addressing, allowing the realization of a quantum repeater. We have performed a detailed feasibility study of our proposal based on tight-binding calculations of quantum dot properties.

arXiv:quant-ph/0609030•Physical Review B•Feb 9, 2007•39 citations

Measurement-based approach to entanglement generation in coupled quantum dots

Avinash Kolli, Brendon W. Lovett, Simon C. Benjamin +1 more

The remarkable phenomenon of measurement-induced quantum entanglement has recently been demonstrated between noninteracting atomic systems [D. L. Moehring et al., Nature (London) 449, 68 (2007)]. In the solid state, the technique may offer a new means of harnessing the strong interactions between neighboring units without the need for precise control over interactions. Recently, we proposed a method for optical parity measurements in a coupled quantum dot system [A. Kolli et al., Phys. Rev. Lett. 97, 250504 (2006)]. Here we perform a comprehensive analytic and numerical study to determine the feasibility of realizing this method using existing technology. We calculate the effects of possible error sources including nonideal photon detectors, ineffective spin-selective excitation, and dot distinguishability (both spatial and spectral). Furthermore, we present an experimental approach for verifying the success of the parity measurement. We conclude that experimental realization of the process should be feasible immediately.

arXiv:0801.2873•Physical Review B•Jan 15, 2009•6 citations

Remotely Controlled Entanglement Generation

Ferran Riera-Sàbat, Pavel Sekatski, Wolfgang Dür

We consider a system of multiple qubits without any quantum control. We show that one can mediate entanglement between different subsystems in a controlled way by adding a (locally) controlled auxiliary system of the same size that couples via an always-on, distant dependent interaction to the system qubits. Solely by changing the internal state of the control system, one can selectively couple it to selected qubits, and ultimately generate different kinds of entanglement within the system. This provides an alternative way for quantum control and quantum gates that does not rely on the ability to switch interactions on and off at will, and can serve as a locally controlled quantum switch where all entanglement patterns can be created. We demonstrate that such an approach also offers an increased error tolerance w.r.t. position fluctuations.

arXiv:2206.10686•Quantum•Jan 24, 2023•9 citations

Spatial entanglement in two-dimensional artificial atoms

Dung Ngoc Pham, Sathwik Bharadwaj, L. R. Ram‐Mohan

Semiconductor quantum dots (QDs) are one of the leading candidates for realizable qubits, as well as for many other advances in quantum computing and quantum communication. The spatial overlapping of wavefunctions describing each single electron in these nanoscale devices results in tunable spatial entanglement. In this article, we explore the case of two electrons in two-dimensional double quantum dot systems. We compute the two-particle wavefunction through a variational method combined with Hermite finite elements and study the spatial entanglement of electrons. We show that symmetry in the geometry of the double quantum dots plays a role in obtaining optimal entanglement, while a broken symmetry can lead to additional resonances in entanglement that are associated with the crossings of states. We also show that one can finely tune the level of spatial entanglement by altering the geometry of the quantum dots or by applying external fields, which corresponds to an “entanglement spectroscopy.” Finally, we study how impurities in the potential profile of the QDs affect the level of entanglement.

Journal of Applied Physics•Feb 8, 2024•1 citation

Generation of multi-photon entanglement

Dong Xie, An Min Wang

We propose a new scheme to generate multi-photon entanglement in two steps. First, we utilize a superconductor to create multi-quantum-dot entanglement; secondly, we use the input photon to transfer it into multi-photon entanglement. Moreover, the maximum probability for the swap of photon and quantum-dot qubits is close to unity for a single input Gaussian photon. More importantly, by mapping the multi-quantum-dot state into coherent states of oscillators, such as cavity modes, the multi-quantum-dot entanglement in our scheme can be protected from the decoherence induced by the noise. Thus, it is possible to generate more than eight spatially separated entangled photons in the realistic experimental conditions.

arXiv:1312.7178•International Journal of Quantum Information•Apr 1, 2015•1 citation
An alternative method is proposed for generating efficiently the entangled states in semiconductor quantum dots by using the spatial phase. The method does not rely on the frequently used dipole–dipole interaction among the qubits at all. It was found that as a result of breaking the selection rule by the spatial phase it enables one to create the entanglement that can never be realized when closely located identical quantum dots are used as qubit gates. In this paper generation of entanglements in two- and three-qubit systems is investigated. The experimental setup based on our approach is much clearer and simpler than that based on the dipole-dipole interaction.
We propose a new idea of generating and controlling quantum coherences among semiconductor quantum dots by using the spatial phase of one single-mode incident laser pulse. Two or three identical quantum dots are employed as qubit gates. Our strategy is to use the spatial phase of the laser pulse at the different positions of the qubits for quantum operations, rather than to utilize dipole-dipole interactions between them. In this work, Hadamard transformation and creation of entanglements in the bipartite and tripartite systems are examined. We predict that with much simpler experimental setup the spatial phase of the laser pulse makes it possible to perform elementary quantum operations that are infeasible by the present-day quantum computer architecture.
Single electron spins in quantum dots are attractive for quantum communication because of their expected long coherence times. We propose a method to create entanglement between two remote spins based on the coincident detection of two photons emitted by the dots. Local nodes of two or more qubits can be realized using the dipole-dipole interaction between trions in neighboring dots and spectral addressing, allowing the realization of a quantum repeater. We have performed a detailed feasibility study of our proposal based on tight-binding calculations of quantum dot properties.
The remarkable phenomenon of measurement-induced quantum entanglement has recently been demonstrated between noninteracting atomic systems [D. L. Moehring et al., Nature (London) 449, 68 (2007)]. In the solid state, the technique may offer a new means of harnessing the strong interactions between neighboring units without the need for precise control over interactions. Recently, we proposed a method for optical parity measurements in a coupled quantum dot system [A. Kolli et al., Phys. Rev. Lett. 97, 250504 (2006)]. Here we perform a comprehensive analytic and numerical study to determine the feasibility of realizing this method using existing technology. We calculate the effects of possible error sources including nonideal photon detectors, ineffective spin-selective excitation, and dot distinguishability (both spatial and spectral). Furthermore, we present an experimental approach for verifying the success of the parity measurement. We conclude that experimental realization of the process should be feasible immediately.
We consider a system of multiple qubits without any quantum control. We show that one can mediate entanglement between different subsystems in a controlled way by adding a (locally) controlled auxiliary system of the same size that couples via an always-on, distant dependent interaction to the system qubits. Solely by changing the internal state of the control system, one can selectively couple it to selected qubits, and ultimately generate different kinds of entanglement within the system. This provides an alternative way for quantum control and quantum gates that does not rely on the ability to switch interactions on and off at will, and can serve as a locally controlled quantum switch where all entanglement patterns can be created. We demonstrate that such an approach also offers an increased error tolerance w.r.t. position fluctuations.
Semiconductor quantum dots (QDs) are one of the leading candidates for realizable qubits, as well as for many other advances in quantum computing and quantum communication. The spatial overlapping of wavefunctions describing each single electron in these nanoscale devices results in tunable spatial entanglement. In this article, we explore the case of two electrons in two-dimensional double quantum dot systems. We compute the two-particle wavefunction through a variational method combined with Hermite finite elements and study the spatial entanglement of electrons. We show that symmetry in the geometry of the double quantum dots plays a role in obtaining optimal entanglement, while a broken symmetry can lead to additional resonances in entanglement that are associated with the crossings of states. We also show that one can finely tune the level of spatial entanglement by altering the geometry of the quantum dots or by applying external fields, which corresponds to an “entanglement spectroscopy.” Finally, we study how impurities in the potential profile of the QDs affect the level of entanglement.
We propose a new scheme to generate multi-photon entanglement in two steps. First, we utilize a superconductor to create multi-quantum-dot entanglement; secondly, we use the input photon to transfer it into multi-photon entanglement. Moreover, the maximum probability for the swap of photon and quantum-dot qubits is close to unity for a single input Gaussian photon. More importantly, by mapping the multi-quantum-dot state into coherent states of oscillators, such as cavity modes, the multi-quantum-dot entanglement in our scheme can be protected from the decoherence induced by the noise. Thus, it is possible to generate more than eight spatially separated entangled photons in the realistic experimental conditions.