Quantum Information Processing with

... ‘transmon’ charge qubits are capacitively coupled to a one-dimensional microwave transmission line resonator which serves as a quantum bus. Single-qubit rotations can be applied through the resonator and their operation is characterized using various benchmarking techniques. Through a virtual photon ...

... ‘transmon’ charge qubits are capacitively coupled to a one-dimensional microwave transmission line resonator which serves as a quantum bus. Single-qubit rotations can be applied through the resonator and their operation is characterized using various benchmarking techniques. Through a virtual photon ...

Entanglement in periodically driven quantum systems

... This has led, e.g., to the investigation of dynamical localization [17, 18] and the coherent destruction of tunneling [19], both of which arise from the interplay of periodic driving and quantum coherence. Arguably the most fascinating trait of quantum mechanics, however, is entanglement. It describ ...

... This has led, e.g., to the investigation of dynamical localization [17, 18] and the coherent destruction of tunneling [19], both of which arise from the interplay of periodic driving and quantum coherence. Arguably the most fascinating trait of quantum mechanics, however, is entanglement. It describ ...

Two Qubits Tavis-Cummings Model Beyond the Rotating Wave

... electrons coupled to a phonon mode of a crystal lattice [3], or super-conducting qubits interacting with a nanomechanical resonator [4, 5], a transmission line resonator [6, 7], or an LC circuit [8, 9]. In the area of quantum optics, the model describing the interaction of a single qubit with a harm ...

... electrons coupled to a phonon mode of a crystal lattice [3], or super-conducting qubits interacting with a nanomechanical resonator [4, 5], a transmission line resonator [6, 7], or an LC circuit [8, 9]. In the area of quantum optics, the model describing the interaction of a single qubit with a harm ...

Multi-particle qubits - Department of Physics — ETH Zurich

... In this thesis we discuss a scheme in which the quantum computer’s logical unit (the qubit) is implemented by a system composed of several elementary particles. We call this system a multi-particle qubit. Several such schemes have already been proposed, e.g. qubits encoded by varying number of spin1 ...

... In this thesis we discuss a scheme in which the quantum computer’s logical unit (the qubit) is implemented by a system composed of several elementary particles. We call this system a multi-particle qubit. Several such schemes have already been proposed, e.g. qubits encoded by varying number of spin1 ...

Decoherence and open quantum systems

... In quantum information theory entanglement is used as a source for many different applications, for instance in quantum cryptography, teleportation schemes or quantum computation. To keep this entanglement in the system as long as possible we have to protect it against different environmental influe ...

... In quantum information theory entanglement is used as a source for many different applications, for instance in quantum cryptography, teleportation schemes or quantum computation. To keep this entanglement in the system as long as possible we have to protect it against different environmental influe ...

Reversible transformations from pure to mixed states and the unique

... subtraction of two known terms, but rather has an autonomous meaning? It turns out that there it is such a possibility and it is offered by quantum information theory: in Ref. 关2兴 we have 1050-2947/2003/67共6兲/062104共9兲/$20.00 ...

... subtraction of two known terms, but rather has an autonomous meaning? It turns out that there it is such a possibility and it is offered by quantum information theory: in Ref. 关2兴 we have 1050-2947/2003/67共6兲/062104共9兲/$20.00 ...

Two-resonator circuit quantum electrodynamics: Dissipative theory

... on the coupled resonator pair. Hence, in this work, we develop a complete dissipative theory for a circuit QED setup consisting of two resonators both dispersively coupled to a single qubit. As a central result, we demonstrate that qubit relaxation affects the resonators in second dispersive order, ...

... on the coupled resonator pair. Hence, in this work, we develop a complete dissipative theory for a circuit QED setup consisting of two resonators both dispersively coupled to a single qubit. As a central result, we demonstrate that qubit relaxation affects the resonators in second dispersive order, ...

Coherent states and projective representation of the linear canonical

... representation in terms of coherent states, Ref. 4 for applications of this treatment of the homogeneous linear canonical transformations, Ref. 5 for an application of the inhomogeneous linear canonical transformations, and Ref. 6 for a relation with Bogoliubov transformations and quasi-free states ...

... representation in terms of coherent states, Ref. 4 for applications of this treatment of the homogeneous linear canonical transformations, Ref. 5 for an application of the inhomogeneous linear canonical transformations, and Ref. 6 for a relation with Bogoliubov transformations and quasi-free states ...

Measurement-Based Quantum Computation

... will see a green slip if he first opens his envelope tomorrow, or saw a green slip if he opened the envelope yesterday. Assuming, of course, that he did not drop the slip into a vat of red ink before looking at it. • To summarize: For the graph state |Gi under discussion, the correct inference from ...

... will see a green slip if he first opens his envelope tomorrow, or saw a green slip if he opened the envelope yesterday. Assuming, of course, that he did not drop the slip into a vat of red ink before looking at it. • To summarize: For the graph state |Gi under discussion, the correct inference from ...

Bulk Locality and Quantum Error Correction in AdS/CFT arXiv

... mentioned in the introduction, that is that no nontrivial operator in the CFT can commute with all local CFT operators on Σ. To avoid this contradiction it must be the case that the representations of φ(x) in different wedges are not really all the same operator on the CFT Hilbert space. We can see ...

... mentioned in the introduction, that is that no nontrivial operator in the CFT can commute with all local CFT operators on Σ. To avoid this contradiction it must be the case that the representations of φ(x) in different wedges are not really all the same operator on the CFT Hilbert space. We can see ...

Approaches to Quantum Error Correction

... 2 The subtleties of quantum errors “Small errors will accumulate and cause the computation to go off track.” Rolf Landauer, 1995, in “Is quantum mechanics useful?” A quantum machine is far more susceptible to making errors then classical digital machines. Not only is a quantum system more prone to d ...

... 2 The subtleties of quantum errors “Small errors will accumulate and cause the computation to go off track.” Rolf Landauer, 1995, in “Is quantum mechanics useful?” A quantum machine is far more susceptible to making errors then classical digital machines. Not only is a quantum system more prone to d ...

Direct characterization of quantum dynamics

... of the system. In general, however, it is unclear if there is a fundamental relationship between QED and QPT, namely whether it is possible to completely characterize the quantum dynamics of arbitrary quantum systems using QED. And, providing the answer is affirmative, how the physical resources sca ...

... of the system. In general, however, it is unclear if there is a fundamental relationship between QED and QPT, namely whether it is possible to completely characterize the quantum dynamics of arbitrary quantum systems using QED. And, providing the answer is affirmative, how the physical resources sca ...

Spin-based quantum computers made by chemistry: hows and whys†

... In writing this review we have assumed a reader who may not be too familiar with this subject, but who is interested in understanding the main ideas and problems, and who is also looking for suggestions for future work in this area. We therefore begin, in section II, by describing briefly what a QIP ...

... In writing this review we have assumed a reader who may not be too familiar with this subject, but who is interested in understanding the main ideas and problems, and who is also looking for suggestions for future work in this area. We therefore begin, in section II, by describing briefly what a QIP ...

QUANTUM COMPUTING: AN OVERVIEW

... pi . In other words, we cannot say deﬁnitely which state the system is in. Therefore some random nature comes into the description of the system. Such a system is said to be in a mixed state while a system whose vector is uniquely speciﬁed is in a pure state. A pure state is a special case of a mixe ...

... pi . In other words, we cannot say deﬁnitely which state the system is in. Therefore some random nature comes into the description of the system. Such a system is said to be in a mixed state while a system whose vector is uniquely speciﬁed is in a pure state. A pure state is a special case of a mixe ...

Demonstration of Entanglement of Electrostatically Coupled Singlet-Triplet Qubits M. D. Shulman

... x and z-axes of the Bloch sphere [11]. Rotations around the z-axis of the Bloch sphere are driven by the exchange splitting, J , between |S〉 and |T0 〉, and rotations around the x-axis are driven by a magnetic field gradient, ∆B z between the electrons. We implement the S-T0 qubit by confining two el ...

... x and z-axes of the Bloch sphere [11]. Rotations around the z-axis of the Bloch sphere are driven by the exchange splitting, J , between |S〉 and |T0 〉, and rotations around the x-axis are driven by a magnetic field gradient, ∆B z between the electrons. We implement the S-T0 qubit by confining two el ...

80, 032307 (2009)

... trapped at the bottom of an optical dipole trap that is generated by a YAG laser with a trap depth of ⬃500 K. The only relevant classical noise taken into account here is the intensity fluctuation of the trapping laser. The power spectrum is adopted from Ref. 关50兴, which can be approximated by S共f兲 ...

... trapped at the bottom of an optical dipole trap that is generated by a YAG laser with a trap depth of ⬃500 K. The only relevant classical noise taken into account here is the intensity fluctuation of the trapping laser. The power spectrum is adopted from Ref. 关50兴, which can be approximated by S共f兲 ...

Braid Topologies for Quantum Computation

... quantum information while simultaneously protecting it from error and loss of quantum coherence due to coupling to the environment. Topological quantum computation (TQC) [1, 2] offers a particularly elegant way to achieve this using quasiparticles which obey nonabelian statistics [3, 4]. These quasi ...

... quantum information while simultaneously protecting it from error and loss of quantum coherence due to coupling to the environment. Topological quantum computation (TQC) [1, 2] offers a particularly elegant way to achieve this using quasiparticles which obey nonabelian statistics [3, 4]. These quasi ...

Decoherence of a Quantum Bit Circuit

... ions[4] have been considered. Their main advantage is their excellent quantum coherence, but their scalability is questionable. The most advanced qubit implementation is based on ions in linear traps, coupled to their longitudinal motion [4] and addressed optically. Solid state electrical circuits h ...

... ions[4] have been considered. Their main advantage is their excellent quantum coherence, but their scalability is questionable. The most advanced qubit implementation is based on ions in linear traps, coupled to their longitudinal motion [4] and addressed optically. Solid state electrical circuits h ...

Detected-jump-error-correcting quantum codes - IAP TU

... attractive. One faces all the problems that are related to the implementation of large numbers of control measurements and recovery operations. It is therefore much more desirable to develop passive error-correcting methods for stabilizing ...

... attractive. One faces all the problems that are related to the implementation of large numbers of control measurements and recovery operations. It is therefore much more desirable to develop passive error-correcting methods for stabilizing ...

Braid Topologies for Quantum Computation

... (TQC) [1, 2] offers a particularly elegant way to achieve this using quasiparticles which obey nonabelian statistics [3, 4]. These quasiparticles, which are expected to arise in a variety of two-dimensional quantum many-body systems [1, 4, 5, 6, 7, 8, 9, 10, 11], have the property that the usual pha ...

... (TQC) [1, 2] offers a particularly elegant way to achieve this using quasiparticles which obey nonabelian statistics [3, 4]. These quasiparticles, which are expected to arise in a variety of two-dimensional quantum many-body systems [1, 4, 5, 6, 7, 8, 9, 10, 11], have the property that the usual pha ...

Computing with Highly Mixed States

... intersection of every pair has dimension less than (1 − poly(m) )2n−k . Then, unless n m satisfies the bound above, there is no collection of unitary operators on C2 that induces all possible permutations of the subspaces. The argument rests upon the representation theory of the symmetric group. 2. ...

... intersection of every pair has dimension less than (1 − poly(m) )2n−k . Then, unless n m satisfies the bound above, there is no collection of unitary operators on C2 that induces all possible permutations of the subspaces. The argument rests upon the representation theory of the symmetric group. 2. ...

Holographic Quantum Error Correcting Codes - Adrian Franco

... is a rank-one projector on the one-dimensional subspace generated by |ψi. Depending on what system we are dealing with, the space of states will have different aspect. For example, if we consider a particle which can move in one dimension, its space of states is spanned by the states {|xi}x∈R , wher ...

... is a rank-one projector on the one-dimensional subspace generated by |ψi. Depending on what system we are dealing with, the space of states will have different aspect. For example, if we consider a particle which can move in one dimension, its space of states is spanned by the states {|xi}x∈R , wher ...

Precisely Timing Dissipative Quantum Information

... starting from any initial state) appears to imply a potentially severe disadvantage: that operations cannot be performed sequentially in time. Steps of a procedure cannot be ...

... starting from any initial state) appears to imply a potentially severe disadvantage: that operations cannot be performed sequentially in time. Steps of a procedure cannot be ...