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

Book Publisher International (a part of SCIENCEDOMAIN International)

Quantum-dot Controlled Electronic Block Triggering a Quantum Computation Procedure: A Recent Study

Vladimir Kirillivich Voronov

Published Aug 27, 2021• 0 citations
Publisher

Abstract

The works that have been devoted to the topic of quantum computer design have been examined. The main issues surrounding the development of a quantum computer are explored. The “up to bottom” concept has been presented and supported as a fundamentally novel way to solve the problem of building a really quantum computer. The technique can be accomplished by using nanotriggers made of two-dimensional materials, such as graphene, to visualise the quantum states of qubits in advance. This refers to the visualisation (materialisation) of all states, including entangled states, which primarily determine the quantum computer's theoretically large mathematical resource. The proposal is for an electronic device block diagram based on “a priory” quantum states of q-bits. It is demonstrated that each realised (visualised) Shor's cell should correspond to an element of the electronic system for the execution of quantum computation procedures. A block containing at least 1010 nanotriggers that act as q-bits in quantum computation and are generated using graphene nanoribbons and controlled by a specific element is included in the device. The latter is a self-organizing quantum dot with two essentially different magnetic states. This quantum dot is made from a compound whose molecules are distinguished by intramolular rearrangement. Nanotriggers are used to create reversible logic gates or blocks. Three triggers are included in each gate to perform logical operations. The offered device is an additional electronic unit implanted in a digital computer that allows the computational process to be implemented in accordance with the requirements of quantum physics.

DOI
10.9734/bpi/ctmcs/v9/4204f

Related papers

Quantum-dot Controlled Electronic Block Triggering a Quantum Computation Procedure

Vladimir Kirillivich Voronov

The works devoted to an issue of quantum computer design have been analyzed.The main problems related to creation of the quantum computer are discussed.A fundamentally new approach to solving the problem of creating a truly quantum computer based on the "up to bottom" strategy has been proposed and justified.The strategy can be implemented by preliminary visualization of the quantum states of qubits using nanotriggers formed from two-dimensional material, in particular, graphene.This refers to the visualization (materialization) of all, including entangled, states, which mainly determine the theoretically possible large mathematical resource of a quantum computer.A block-diagram of the electronic device based on "a priory" quantum states of q-bits is proposed.It is shown that for implementation of quantum computation procedure, each materialized (visualized) Shor's cell should correspond to an element of the electronic scheme.The device includes a block containing at least 10 10 nanotriggers that perform a role of q-bits of quantum computation, which are created using graphene nanoribbons and controlled by a special element.The latter represents a self-organizing quantum dot having two essentially different states in terms of magnetic properties.This quantum dot is prepared on the basis of a compound, the molecules of which are characterized by the intramolular rearrangement.The nanotriggers are employed to form reversible logic blocks or gates.Each gate contains three triggers to perform logical operations.The offered device is an additional electronic unit that is embedded in a digital computer, which makes it possible to implement the computational process in accordance with the requirements of the provisions of quantum physics.

International Journal of Information Technology and Computer Science•Apr 8, 2020•5 citations

Achieving quantum computation with quantum dot spin qubits

Sebastian Mehl, David Peter Divincenzo

A two-level quantum system is the building block of a quantum computer. This pair of quantum states defines the computational unit of a quantum computer, and it is called a quantum bit or qubit in analogy to the bit that is the binary unit of a classical computer. The spin of a single electron naturally defines such a two-level quantum system. A quantum dot can be tuned to the single-electron regime, and an array of singly occupied quantum dots provides a multi-qubit register. This thesis describes the multielectron encoding of a spin qubit using a pair or a trio of quantum dots, and it analyzes the coherence properties and manipulation protocols of this system. The singlet-triplet qubit, coded using the singlet state and the spinless triplet state of a pair of singly occupied quantum dots, can be controlled all electrically when applying voltages to gates close to the quantum dot structure. Rapid, subnanosecond modifications of the double quantum dot's charge configuration have been realized successfully. A small magnetic field gradient across the double quantum dot enables universal qubit control. Two modifications of the normal singlet-triplet encoding are introduced. (1) The six-electron configuration of a double quantum dot encodes a singlet-triplet qubit in the same way as for the two-electron double quantum dot. Two electrons at each quantum dot are irrelevant for the qubit manipulations because they are paired in a singlet state; the remaining two electrons encode the qubit. The qubit's wave function is immune to charge noise at moderate out-of-plane magnetic fields. (2) A singlet-triplet qubit encoded using two quantum dots of different sizes has an orbital state degeneracy of the singlet state and the spinless triplet state at finite out-of-plane magnetic fields. Spin-orbit interactions lift this state degeneracy, while the magnitude of the state coupling is determined by the size difference of the QDs. This setup enables the manipulations of singlet-triplet qubits without the need for magnetic field gradients. Finally, two-qubit gates between singlet-triplet qubits are proposed that use mediated exchange interactions via one quantum state. These operations are well controlled and highly noise insensitive. Orbital interactions alone can control spin qubits coded in a three electron Hilbert space. For example, the exchange-only qubit is encoded using three singly occupied quantum dots. The exchange interactions of two quantum dot pairs need to be modified to manipulate this qubit. The noise sensitivity of the exchange-only qubit is discussed. Alternatively, a three-electron qubit at a double quantum dot can be operated when single electrons are transferred between the quantum dots. Fast, subnanosecond manipulations of the double quantum dot's charge configuration are required to realize single-qubit gates. A novel two-qubit pulse gate for the three-electron double quantum dot qubit is proposed.

•Jan 1, 2014•0 citations

Self-assembled nanoelectronic quantum computer based on the Rashba effect in quantum dots

S. Bandyopadhyay

Quantum computers promise vastly enhanced computational power and an uncanny ability to solve classically intractable problems. However, few proposals exist for robust, solid-state implementation of such computers where the quantum gates are sufficiently miniaturized to have nanometer-scale dimensions. Here I present a new approach whereby a complete computer with nanoscale gates might be self-assembled using chemical synthesis. Specifically, I demonstrate how to self-assemble the fundamental unit of this quantum computer---a two-qubit universal quantum gate---based on two exchange coupled multilayered quantum dots. Then I show how these gates can be wired using thiolated conjugated molecules as electrical connectors. Each quantum dot in this architecture consists of ferromagnet-semiconductor-ferromagnet layers. The ground state in the semiconductor layer is spin split because of the Rashba interaction and the spin-splitting energy can be varied by an external electrostatic potential applied to the dot. A spin polarized electron is injected into each dot from one of the ferromagnetic layers and trapped by Coulomb blockade. Its spin orientation encodes a qubit. Arbitrary qubit rotations are effected by bringing the spin-splitting energy in a target quantum dot in resonance with a global ac magnetic field by applying a potential pulse of appropriate amplitude and duration to the dot. The controlled dynamics of the universal two-qubit rotation operation can be realized by exploiting the exchange coupling with the nearest-neighboring dot. The qubit (spin orientation) is read via the current induced between the ferromagnetic layers under an applied potential. The ferromagnetic layers act as ``polarizers'' and ``analyzers'' for spin injection and detection. A complete prescription for initialization of the computer and data input/output operations is presented. This paradigm, to the best of our knowledge, draws together two great recent scientific advances: one in materials science (nanoscale self-assembly) and the other in information science (quantum computing).

arXiv:quant-ph/9910032•Physical review. B, Condensed matter•May 15, 2000•113 citations

Quantum computation with graphene nanoribbon

Guo‐Ping Guo, Zhirong Lin, Tao Tu +3 more

We propose a scheme to implement quantum computation in graphene nanoribbon (GNR). It is shown that an electron or hole can be naturally localized in each zigzag region for a GNR with a sequence of Z-shaped structures, without using confined gates. A one-dimensional graphene quantum dot chain is formed in such a GNR, where an electron or hole spin can be used as a qubit. The coupling interaction between neighboring qubits is found to be of the always-on Heisenberg type. By exploiting the bang–bang control strategy and the decoherence-free subspaces encoding method, universal quantum gates are argued to be realizable with the present techniques.

arXiv:0808.1618•New Journal of Physics•Dec 3, 2009•62 citations

Quantum-dot computing

Gerard J Milburn

A quantum computer would put the latest PC to shame. Not only would such a device be faster than a conventional computer, but by exploiting the quantum-mechanical principle of superposition it could change the way we think about information processing. However, two key goals need to be met before a quantum computer becomes reality. The first is to be able to control the state of a single quantum bit (or “qubit”) and the second is to build a two-qubit gate that can produce “entanglement” between the qubit states. Now Xiaoqin Li at the University of Michigan and co-workers have passed a significant milestone in solid-state quantum computing by demonstrating a two-qubit logic gate using electron – hole pairs in a single quantum dot (X Li et al. 2003 Science 301 809–811).

Physics World•Oct 1, 2003•6 citations

Colloquium : Advances in automation of quantum dot devices control

Justyna P. Zwolak, Jacob M. Taylor

Arrays of quantum dots (QDs) are a promising candidate system to realize scalable, coupled qubit systems and serve as a fundamental building block for quantum computers. In such semiconductor quantum systems, devices now have tens of individual electrostatic and dynamical voltages that must be carefully set to localize the system into the single-electron regime and to realize good qubit operational performance. The mapping of requisite QD locations and charges to gate voltages presents a challenging classical control problem. With an increasing number of QD qubits, the relevant parameter space grows sufficiently to make heuristic control unfeasible. In recent years, there has been considerable effort to automate device control that combines script-based algorithms with machine learning (ML) techniques. In this Colloquium, a comprehensive overview of the recent progress in the automation of QD device control is presented, with a particular emphasis on silicon- and GaAs-based QDs formed in two-dimensional electron gases. Combining physics-based modeling with modern numerical optimization and ML has proven effective in yielding efficient, scalable control. Further integration of theoretical, computational, and experimental efforts with computer science and ML holds vast potential in advancing semiconductor and other platforms for quantum computing.

arXiv:2112.09362•Reviews of Modern Physics•Feb 17, 2023•62 citations
The works that have been devoted to the topic of quantum computer design have been examined. The main issues surrounding the development of a quantum computer are explored. The “up to bottom” concept has been presented and supported as a fundamentally novel way to solve the problem of building a really quantum computer. The technique can be accomplished by using nanotriggers made of two-dimensional materials, such as graphene, to visualise the quantum states of qubits in advance. This refers to the visualisation (materialisation) of all states, including entangled states, which primarily determine the quantum computer's theoretically large mathematical resource. The proposal is for an electronic device block diagram based on “a priory” quantum states of q-bits. It is demonstrated that each realised (visualised) Shor's cell should correspond to an element of the electronic system for the execution of quantum computation procedures. A block containing at least 1010 nanotriggers that act as q-bits in quantum computation and are generated using graphene nanoribbons and controlled by a specific element is included in the device. The latter is a self-organizing quantum dot with two essentially different magnetic states. This quantum dot is made from a compound whose molecules are distinguished by intramolular rearrangement. Nanotriggers are used to create reversible logic gates or blocks. Three triggers are included in each gate to perform logical operations. The offered device is an additional electronic unit implanted in a digital computer that allows the computational process to be implemented in accordance with the requirements of quantum physics.
The works devoted to an issue of quantum computer design have been analyzed.The main problems related to creation of the quantum computer are discussed.A fundamentally new approach to solving the problem of creating a truly quantum computer based on the "up to bottom" strategy has been proposed and justified.The strategy can be implemented by preliminary visualization of the quantum states of qubits using nanotriggers formed from two-dimensional material, in particular, graphene.This refers to the visualization (materialization) of all, including entangled, states, which mainly determine the theoretically possible large mathematical resource of a quantum computer.A block-diagram of the electronic device based on "a priory" quantum states of q-bits is proposed.It is shown that for implementation of quantum computation procedure, each materialized (visualized) Shor's cell should correspond to an element of the electronic scheme.The device includes a block containing at least 10 10 nanotriggers that perform a role of q-bits of quantum computation, which are created using graphene nanoribbons and controlled by a special element.The latter represents a self-organizing quantum dot having two essentially different states in terms of magnetic properties.This quantum dot is prepared on the basis of a compound, the molecules of which are characterized by the intramolular rearrangement.The nanotriggers are employed to form reversible logic blocks or gates.Each gate contains three triggers to perform logical operations.The offered device is an additional electronic unit that is embedded in a digital computer, which makes it possible to implement the computational process in accordance with the requirements of the provisions of quantum physics.
A two-level quantum system is the building block of a quantum computer. This pair of quantum states defines the computational unit of a quantum computer, and it is called a quantum bit or qubit in analogy to the bit that is the binary unit of a classical computer. The spin of a single electron naturally defines such a two-level quantum system. A quantum dot can be tuned to the single-electron regime, and an array of singly occupied quantum dots provides a multi-qubit register. This thesis describes the multielectron encoding of a spin qubit using a pair or a trio of quantum dots, and it analyzes the coherence properties and manipulation protocols of this system. The singlet-triplet qubit, coded using the singlet state and the spinless triplet state of a pair of singly occupied quantum dots, can be controlled all electrically when applying voltages to gates close to the quantum dot structure. Rapid, subnanosecond modifications of the double quantum dot's charge configuration have been realized successfully. A small magnetic field gradient across the double quantum dot enables universal qubit control. Two modifications of the normal singlet-triplet encoding are introduced. (1) The six-electron configuration of a double quantum dot encodes a singlet-triplet qubit in the same way as for the two-electron double quantum dot. Two electrons at each quantum dot are irrelevant for the qubit manipulations because they are paired in a singlet state; the remaining two electrons encode the qubit. The qubit's wave function is immune to charge noise at moderate out-of-plane magnetic fields. (2) A singlet-triplet qubit encoded using two quantum dots of different sizes has an orbital state degeneracy of the singlet state and the spinless triplet state at finite out-of-plane magnetic fields. Spin-orbit interactions lift this state degeneracy, while the magnitude of the state coupling is determined by the size difference of the QDs. This setup enables the manipulations of singlet-triplet qubits without the need for magnetic field gradients. Finally, two-qubit gates between singlet-triplet qubits are proposed that use mediated exchange interactions via one quantum state. These operations are well controlled and highly noise insensitive. Orbital interactions alone can control spin qubits coded in a three electron Hilbert space. For example, the exchange-only qubit is encoded using three singly occupied quantum dots. The exchange interactions of two quantum dot pairs need to be modified to manipulate this qubit. The noise sensitivity of the exchange-only qubit is discussed. Alternatively, a three-electron qubit at a double quantum dot can be operated when single electrons are transferred between the quantum dots. Fast, subnanosecond manipulations of the double quantum dot's charge configuration are required to realize single-qubit gates. A novel two-qubit pulse gate for the three-electron double quantum dot qubit is proposed.
Quantum computers promise vastly enhanced computational power and an uncanny ability to solve classically intractable problems. However, few proposals exist for robust, solid-state implementation of such computers where the quantum gates are sufficiently miniaturized to have nanometer-scale dimensions. Here I present a new approach whereby a complete computer with nanoscale gates might be self-assembled using chemical synthesis. Specifically, I demonstrate how to self-assemble the fundamental unit of this quantum computer---a two-qubit universal quantum gate---based on two exchange coupled multilayered quantum dots. Then I show how these gates can be wired using thiolated conjugated molecules as electrical connectors. Each quantum dot in this architecture consists of ferromagnet-semiconductor-ferromagnet layers. The ground state in the semiconductor layer is spin split because of the Rashba interaction and the spin-splitting energy can be varied by an external electrostatic potential applied to the dot. A spin polarized electron is injected into each dot from one of the ferromagnetic layers and trapped by Coulomb blockade. Its spin orientation encodes a qubit. Arbitrary qubit rotations are effected by bringing the spin-splitting energy in a target quantum dot in resonance with a global ac magnetic field by applying a potential pulse of appropriate amplitude and duration to the dot. The controlled dynamics of the universal two-qubit rotation operation can be realized by exploiting the exchange coupling with the nearest-neighboring dot. The qubit (spin orientation) is read via the current induced between the ferromagnetic layers under an applied potential. The ferromagnetic layers act as ``polarizers'' and ``analyzers'' for spin injection and detection. A complete prescription for initialization of the computer and data input/output operations is presented. This paradigm, to the best of our knowledge, draws together two great recent scientific advances: one in materials science (nanoscale self-assembly) and the other in information science (quantum computing).
We propose a scheme to implement quantum computation in graphene nanoribbon (GNR). It is shown that an electron or hole can be naturally localized in each zigzag region for a GNR with a sequence of Z-shaped structures, without using confined gates. A one-dimensional graphene quantum dot chain is formed in such a GNR, where an electron or hole spin can be used as a qubit. The coupling interaction between neighboring qubits is found to be of the always-on Heisenberg type. By exploiting the bang–bang control strategy and the decoherence-free subspaces encoding method, universal quantum gates are argued to be realizable with the present techniques.
A quantum computer would put the latest PC to shame. Not only would such a device be faster than a conventional computer, but by exploiting the quantum-mechanical principle of superposition it could change the way we think about information processing. However, two key goals need to be met before a quantum computer becomes reality. The first is to be able to control the state of a single quantum bit (or “qubit”) and the second is to build a two-qubit gate that can produce “entanglement” between the qubit states. Now Xiaoqin Li at the University of Michigan and co-workers have passed a significant milestone in solid-state quantum computing by demonstrating a two-qubit logic gate using electron – hole pairs in a single quantum dot (X Li et al. 2003 Science 301 809–811).
Arrays of quantum dots (QDs) are a promising candidate system to realize scalable, coupled qubit systems and serve as a fundamental building block for quantum computers. In such semiconductor quantum systems, devices now have tens of individual electrostatic and dynamical voltages that must be carefully set to localize the system into the single-electron regime and to realize good qubit operational performance. The mapping of requisite QD locations and charges to gate voltages presents a challenging classical control problem. With an increasing number of QD qubits, the relevant parameter space grows sufficiently to make heuristic control unfeasible. In recent years, there has been considerable effort to automate device control that combines script-based algorithms with machine learning (ML) techniques. In this Colloquium, a comprehensive overview of the recent progress in the automation of QD device control is presented, with a particular emphasis on silicon- and GaAs-based QDs formed in two-dimensional electron gases. Combining physics-based modeling with modern numerical optimization and ML has proven effective in yielding efficient, scalable control. Further integration of theoretical, computational, and experimental efforts with computer science and ML holds vast potential in advancing semiconductor and other platforms for quantum computing.