31 research outputs found

    Cluster state generation in one-dimensional Kitaev honeycomb model via shortcut to adiabaticity

    Full text link
    We propose a mean to obtain computationally useful resource states also known as cluster states, for measurement-based quantum computation, via transitionless quantum driving algorithm. The idea is to cool the system to its unique ground state and tune some control parameters to arrive at computationally useful resource state, which is in one of the degenerate ground states. Even though there is set of conserved quantities already present in the model Hamiltonian, which prevents the instantaneous state to go to any other eigenstate subspaces, one cannot quench the control parameters to get the desired state. In that case, the state will not evolve. With involvement of the shortcut Hamiltonian, we obtain cluster states in fast-forward manner. We elaborate our proposal in the one-dimensional Kitaev honeycomb model, and show that the auxillary Hamiltonian needed for the counterdiabatic driving is of M-body interaction.Comment: 13 pages, 3 figures. Added detailed derivation to arrive at the shortcut Hamiltonian plus numerical simulations. Invited manuscript to be appeared in Focus on Shortcuts to Adiabaticity, NJP (IOP

    Measurement-Based Quantum Computation on Two-Body Interacting Qubits with Adiabatic Evolution

    Full text link
    A cluster state cannot be a unique ground state of a two-body interacting Hamiltonian. Here, we propose the creation of a cluster state of logical qubits encoded in spin-1/2 particles by adiabatically weakening two-body interactions. The proposal is valid for any spatial dimensional cluster states. Errors induced by thermal fluctuations and adiabatic evolution within finite time can be eliminated ensuring fault-tolerant quantum computing schemes.Comment: title updated, introduction and discussions sections update

    SKIRTING AROUND THE NO-GO THEOREM IN MEASUREMENT-BASED QUANTUM COMPUTATION

    Get PDF
    Master'sMASTER OF SCIENC

    Floquet stroboscopic divisibility in non-Markovian dynamics

    Full text link
    We provide a general discussion of the Liouvillian spectrum for a system coupled to a non-Markovian bath using Floquet theory. This approach is suitable when the system is described by a time-convolutionless master equation with time-periodic rates. Surprisingly, the periodic nature of rates allow us to have a stroboscopic divisible dynamical map at discrete times, which we refer to as Floquet stroboscopic divisibility. We illustrate the general theory for a Schr\"odinger cat which is roaming inside a non-Markovian bath, and demonstrate the appearance of stroboscopic revival of the cat at later time after its death. Our theory may have profound implications in entropy production in non-equilibrium systems.Comment: We changed the title and explained in more detail the definition of non-Markovian dynamics used in the manuscrip

    Quantum computer-aided design of quantum optics hardware

    Get PDF
    The parameters of a quantum system grow exponentially with the number of involved quantum particles. Hence, the associated memory requirement to store or manipulate the underlying wavefunction goes well beyond the limit of the best classical computers for quantum systems composed of a few dozen particles, leading to serious challenges in their numerical simulation. This implies that the verification and design of new quantum devices and experiments are fundamentally limited to small system size. It is not clear how the full potential of large quantum systems can be exploited. Here, we present the concept of quantum computer designed quantum hardware and apply it to the field of quantum optics. Specifically, we map complex experimental hardware for high-dimensional, many-body entangled photons into a gate-based quantum circuit. We show explicitly how digital quantum simulation of Boson sampling experiments can be realized. We then illustrate how to design quantum-optical setups for complex entangled photonic systems, such as high-dimensional Greenberger–Horne–Zeilinger states and their derivatives. Since photonic hardware is already on the edge of quantum supremacy and the development of gate-based quantum computers is rapidly advancing, our approach promises to be a useful tool for the future of quantum device design

    Mutual information-assisted Adaptive Variational Quantum Eigensolver

    Full text link
    Adaptive construction of ansatz circuits offers a promising route towards applicable variational quantum eigensolvers (VQE) on near-term quantum hardware. Those algorithms aim to build up optimal circuits for a certain problem. Ansatz circuits are adaptively constructed by selecting and adding entanglers from a predefined pool in those algorithms. In this work, we propose a way to construct entangler pools with reduced size for those algorithms by leveraging classical algorithms. Our method uses mutual information (MI) between the qubits in classically approximated ground state to rank and screen the entanglers. The density matrix renormalization group (DMRG) is employed for classical precomputation in this work. We corroborate our method numerically on small molecules. Our numerical experiments show that a reduced entangler pool with a small portion of the original entangler pool can achieve same numerical accuracy. We believe that our method paves a new way for adaptive construction of ansatz circuits for variational quantum algorithms.Comment: 8 pages, 11 figure

    Quantum computer-aided design of quantum optics hardware

    Get PDF
    The parameters of a quantum system grow exponentially with the number of involved quantum particles. Hence, the associated memory requirement to store or manipulate the underlying wavefunction goes well beyond the limit of the best classical computers for quantum systems composed of a few dozen particles, leading to serious challenges in their numerical simulation. This implies that the verification and design of new quantum devices and experiments are fundamentally limited to small system size. It is not clear how the full potential of large quantum systems can be exploited. Here, we present the concept of quantum computer designed quantum hardware and apply it to the field of quantum optics. Specifically, we map complex experimental hardware for high-dimensional, many-body entangled photons into a gate-based quantum circuit. We show explicitly how digital quantum simulation of Boson sampling experiments can be realized. We then illustrate how to design quantum-optical setups for complex entangled photonic systems, such as high-dimensional Greenberger–Horne–Zeilinger states and their derivatives. Since photonic hardware is already on the edge of quantum supremacy and the development of gate-based quantum computers is rapidly advancing, our approach promises to be a useful tool for the future of quantum device design

    Investigation of Japanese Encephalitis Virus Infection in Bogalay Township, Myanmar in 1999

    Get PDF
    An investigation was in Nyi-naung-wa village, Bogalay township for Japanese encephalitis (JE) virus infection and the possibility of a JE outbreak. JE virus antibody was determined among the pigs and the people living near the pig farms in that village and at an adjacent village as a control. The known JE virus vector Culex mosquito species were also identified in both villages. Haemagglutination inhibition (HAI) methods were used for the detectioon of JE and dengue antibodies. Homotypic or monotypic JE antibodies were detected in 33% of the pigs tested. No homotypic nor monotypic JE antibodis was detected among the villagers. Although there was no JE virus infection among the people, because of the presence of JE virus infection among the pigs and the presence of Culex mosquito vector in that area, the possibility of a JE outbreak in humans in that area, if the number of pig breeding per household increase and the mosquito density become higher is discussed
    corecore