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

Coherent control of a qubit for a rotation gate operation in photonic crystals

Hiroyuki Nihei, Akihiro Okamoto

Published Jan 1, 2012• 0 citations
OpenAlex

Abstract

We have developed a method of controlling the quantum state of an impurity atom embedded in photonic crystals that can be used as a single-qubit rotation gate, one of the universal quantum logic gates, using the coherent control of spontaneous emission from the embedded atom.

Related papers

Optical design of a qubit embedded in photonic crystals for rotation gate operations

Hiroyuki Nihei, Atsushi Okamoto

We have optimized the optical design parameters of a qubit composed of excited states of an atom embedded in photonic crystals for operating rotation gates, using the coherent control of spontaneous emission from the atom.

International Conference on Numerical Simulation of Optoelectronic Devices (NUSOD)•Aug 1, 2012•0 citations

Quantum information processing using nanoscale objects embedded in photonic crystals

Hiroyuki Nihei, Atsushi Okamoto

We have demonstrated the coherent control of nanoscale objects (such as quantum dots) embedded in photonic crystals, which provides a basis for a one-qubit phase rotation gate that is one of the universal quantum logic gates for quantum information processing. In this demonstration, the quantum electrodynamics of the atomic system is calculated by the Schrödinger equation. Using the results of the calculation, the quantum electrodynamics is graphically represented by a Bloch sphere. This shows that the quantum state is rotated on the Bloch sphere, and this rotation is stopped or started, depending on the laser phase, which can act as a one-qubit phase rotation gate.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Sep 7, 2007•0 citations

Coherent control of spontaneous emission near a photonic band edge: A qubit for quantum computation

Mesfin Woldeyohannes, Sajeev John

We demonstrate the coherent control of spontaneous emission for a three-level atom located within a photonic band-gap structure with one resonant frequency near the edge of the photonic band gap. Spontaneous emission from the three-level atom can be totally suppressed or strongly enhanced depending on the relative phase between the steady-state control laser coupling the two upper levels and the pump laser pulse used to create an excited state of the atom in the form of a coherent superposition of the two upper levels. Unlike the free-space case, the steady-state inversion of the atomic system is strongly dependent on the externally prescribed initial conditions. This nonzero steady-state population is achieved by virtue of the localization of light in the vicinity of the emitting atom. It is robust to decoherence effects provided that the Rabi frequency of the control laser field-atom interaction exceeds the rate of dephasing interactions. As a result, such a system may be relevant for a single-atom, phase-sensitive, optical memory device on the atomic scale. The protected electric dipole within the photonic band gap provides a basis for a qubit to encode information for quantum computations.

Physical Review A•Dec 1, 1999•143 citations

Ultralow-loss optical quantum information processing in photonic bandgap devices

Hiroyuki Nihei, Atsushi Okamoto

We have demonstrated the coherent control of photonic bandgap (PBG) devices composed of a three-level atom embedded in three-dimensional PBG structures, which enables us to strongly suppress the loss of quantum information not only during its storage but also during its processing. We find that this ultralow-loss optical quantum information processing can be realized by generating the upper atomic level splitting inside the PBG and by tuning one of the split levels to a dark line in the emission spectrum (zeros in the spectrum at certain values of the emitted photon frequency). Furthermore, we show that the coherent control may provide a basis for the universal quantum logic gate operation in quantum computing.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•May 4, 2007•1 citation

Spontaneous emission from a four-level atom embedded in photonic crystals via quantum interference

Rong Tan, Gao‐xiang Li

The spontaneous emission of a four-level atom embedded in a one-dimensional photonic crystal is investigated. The atom has two upper levels coupled by the same vacuum modes to a common lower level and is driven by a coherent field to an auxiliary level. Spontaneous emission can be suppressed significantly due to the combinational influences of the interference effect and the band edge effect. The radiation field emitted by the atom is also studied. Spontaneous emission can be modified by controlling the Rabi frequency of the driving.

Journal of Modern Optics•Aug 15, 2005•3 citations

Controlling a photon with a solid-state quantum bit

Edo Waks A, Hyochul Kim, Ranojoy Bose +3 more

Generating strong interactions between single quanta of light and matter is central to quantum information science, and a key component of quantum computers and long-distance quantum networks. In quantum information processing, these interactions are required to create elementary logic operations (quantum gates) between stationary matter quantum bits (qubits) and photonic qubits that can be transmitted over long distances. Efficient quantum gates between photonic and matter qubits are a crucial enabler for a broad range of applications that include robust quantum networks, nondestructive quantum measurements, and strong photon-photon interactions. So far these qubit-photon gates have been achieved using single atoms and at microwave frequencies in circuit QED systems. Their implementation with solidstate quantum emitters, however, has remained a difficult challenge. We demonstrate that the qubit state of a photon can be controlled by a single solid-state qubit composed of a quantum dot (QD) strongly coupled to an optical nanocavity. We show that the QD acts as a coherently controllable qubit system that conditionally flips the polarization of a photon reflected from the cavity mode on picosecond timescales. This operation implements a controlled NOT (cNOT) logic gate between the QD and the incident photon, which is a universal quantum operation that can serve as a general light-matter interface for remote entanglements and quantum computations. Our results represent an important step towards an all solid-state implementation of quantum networks and quantum computers, and provide a versatile approach for controlling and probing interactions between a photon and a single quantum emitter on ultra-fast timescales.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Sep 12, 2014•0 citations
We have demonstrated the coherent control of nanoscale objects (such as quantum dots) embedded in photonic crystals, which provides a basis for a one-qubit phase rotation gate that is one of the universal quantum logic gates for quantum information processing. In this demonstration, the quantum electrodynamics of the atomic system is calculated by the Schrödinger equation. Using the results of the calculation, the quantum electrodynamics is graphically represented by a Bloch sphere. This shows that the quantum state is rotated on the Bloch sphere, and this rotation is stopped or started, depending on the laser phase, which can act as a one-qubit phase rotation gate.
We demonstrate the coherent control of spontaneous emission for a three-level atom located within a photonic band-gap structure with one resonant frequency near the edge of the photonic band gap. Spontaneous emission from the three-level atom can be totally suppressed or strongly enhanced depending on the relative phase between the steady-state control laser coupling the two upper levels and the pump laser pulse used to create an excited state of the atom in the form of a coherent superposition of the two upper levels. Unlike the free-space case, the steady-state inversion of the atomic system is strongly dependent on the externally prescribed initial conditions. This nonzero steady-state population is achieved by virtue of the localization of light in the vicinity of the emitting atom. It is robust to decoherence effects provided that the Rabi frequency of the control laser field-atom interaction exceeds the rate of dephasing interactions. As a result, such a system may be relevant for a single-atom, phase-sensitive, optical memory device on the atomic scale. The protected electric dipole within the photonic band gap provides a basis for a qubit to encode information for quantum computations.
We have demonstrated the coherent control of photonic bandgap (PBG) devices composed of a three-level atom embedded in three-dimensional PBG structures, which enables us to strongly suppress the loss of quantum information not only during its storage but also during its processing. We find that this ultralow-loss optical quantum information processing can be realized by generating the upper atomic level splitting inside the PBG and by tuning one of the split levels to a dark line in the emission spectrum (zeros in the spectrum at certain values of the emitted photon frequency). Furthermore, we show that the coherent control may provide a basis for the universal quantum logic gate operation in quantum computing.
The spontaneous emission of a four-level atom embedded in a one-dimensional photonic crystal is investigated. The atom has two upper levels coupled by the same vacuum modes to a common lower level and is driven by a coherent field to an auxiliary level. Spontaneous emission can be suppressed significantly due to the combinational influences of the interference effect and the band edge effect. The radiation field emitted by the atom is also studied. Spontaneous emission can be modified by controlling the Rabi frequency of the driving.
Generating strong interactions between single quanta of light and matter is central to quantum information science, and a key component of quantum computers and long-distance quantum networks. In quantum information processing, these interactions are required to create elementary logic operations (quantum gates) between stationary matter quantum bits (qubits) and photonic qubits that can be transmitted over long distances. Efficient quantum gates between photonic and matter qubits are a crucial enabler for a broad range of applications that include robust quantum networks, nondestructive quantum measurements, and strong photon-photon interactions. So far these qubit-photon gates have been achieved using single atoms and at microwave frequencies in circuit QED systems. Their implementation with solidstate quantum emitters, however, has remained a difficult challenge. We demonstrate that the qubit state of a photon can be controlled by a single solid-state qubit composed of a quantum dot (QD) strongly coupled to an optical nanocavity. We show that the QD acts as a coherently controllable qubit system that conditionally flips the polarization of a photon reflected from the cavity mode on picosecond timescales. This operation implements a controlled NOT (cNOT) logic gate between the QD and the incident photon, which is a universal quantum operation that can serve as a general light-matter interface for remote entanglements and quantum computations. Our results represent an important step towards an all solid-state implementation of quantum networks and quantum computers, and provide a versatile approach for controlling and probing interactions between a photon and a single quantum emitter on ultra-fast timescales.