Effective Quantum Spin Systems with Trapped Ions
... the distance between ions is not constant. We can, however, define an averaged lattice constant d0 , to understand the qualitative properties of the vibrational modes. We have two cases, depending on the orientation of the pushing forces: (a) Axial force. The equilibrium position of the ions are suc ...
... the distance between ions is not constant. We can, however, define an averaged lattice constant d0 , to understand the qualitative properties of the vibrational modes. We have two cases, depending on the orientation of the pushing forces: (a) Axial force. The equilibrium position of the ions are suc ...
Invitation to Local Quantum Physics
... The Bisognano-Wichmann Theorem The PCT theorem was used by J. Bisognano and E. Wichmann in 1976 to derive a structural result that is of fundamental importance for the application of Tomita-Takesaki modular theory in relativistic quantum field theory. Let W be a space-like wedge in space-time, i.e. ...
... The Bisognano-Wichmann Theorem The PCT theorem was used by J. Bisognano and E. Wichmann in 1976 to derive a structural result that is of fundamental importance for the application of Tomita-Takesaki modular theory in relativistic quantum field theory. Let W be a space-like wedge in space-time, i.e. ...
Giovannini, D., Romero, J., Leach, J., Dudley, A, Forbes, A, and
... can be extracted from a physical system is fundamentally limited by the uncertainty relations [3,4]. In this context, MUBs acquire a fundamental relevance because they serve as a test bed with which one can explore general uncertainty relations and, ultimately, complementarity [5]. Some important qu ...
... can be extracted from a physical system is fundamentally limited by the uncertainty relations [3,4]. In this context, MUBs acquire a fundamental relevance because they serve as a test bed with which one can explore general uncertainty relations and, ultimately, complementarity [5]. Some important qu ...
The Philosophy behind Quantum Gravity
... rest – must always be described entirely on classical lines, and consequently kept outside the system subject to quantum mechanical treatment. The point is that we can treat a measuring apparatus (or part of this) as a quantum system, but only when some other system is then treated classically. This ...
... rest – must always be described entirely on classical lines, and consequently kept outside the system subject to quantum mechanical treatment. The point is that we can treat a measuring apparatus (or part of this) as a quantum system, but only when some other system is then treated classically. This ...
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... The above data show that we have succeeded with the conditional gate operation. However, to understand our results more quantitatively, we compare the data with simulation data obtained by numerically calculating the time evolution of the density matrix. The results of the simulation are shown as bl ...
... The above data show that we have succeeded with the conditional gate operation. However, to understand our results more quantitatively, we compare the data with simulation data obtained by numerically calculating the time evolution of the density matrix. The results of the simulation are shown as bl ...
Self-consistent approach for calculations of exciton binding energy
... relative two-dimensional in-plane motion of the exciton. Effective potentials entering these equations have to be found self-consistently along with the wave functions. This approach has a number of advantages compared to the previous methods. First of all, in its most general statement it must give ...
... relative two-dimensional in-plane motion of the exciton. Effective potentials entering these equations have to be found self-consistently along with the wave functions. This approach has a number of advantages compared to the previous methods. First of all, in its most general statement it must give ...
Quantum Computing and Communications
... Quantum computing and communications is one of the promising new fields at the dawn of the new millennium. This emerging topic has reached the age when not only physicists and mathematicians but engineers become more and more interested in it. This book is based on the first semester of a two-semest ...
... Quantum computing and communications is one of the promising new fields at the dawn of the new millennium. This emerging topic has reached the age when not only physicists and mathematicians but engineers become more and more interested in it. This book is based on the first semester of a two-semest ...
Quantum error-correction in black holes
... on A.code So, for any bipartition, the entanglement entropyinformation science, it may b Five qubit alue. Let | i be a perfect state, a A quantum be a subseterror-correcting of spins with |A| n by a standard notation [[n code mplement of A. Since A is maximally with B, quantum the entangled total ...
... on A.code So, for any bipartition, the entanglement entropyinformation science, it may b Five qubit alue. Let | i be a perfect state, a A quantum be a subseterror-correcting of spins with |A| n by a standard notation [[n code mplement of A. Since A is maximally with B, quantum the entangled total ...
Unconditionally Secure Quantum Signatures
... digital signature algorithm (DSA) [19] and the elliptic curve digital signature algorithm (ECDSA) [20], which have been the standard in the U.S. since 1998. Although slightly different from RSA encryption, the general principle is the same, with security derived from the assumed computational diffic ...
... digital signature algorithm (DSA) [19] and the elliptic curve digital signature algorithm (ECDSA) [20], which have been the standard in the U.S. since 1998. Although slightly different from RSA encryption, the general principle is the same, with security derived from the assumed computational diffic ...
Topological order at finite temperature?
... above the energy barrier: no topological protection ...
... above the energy barrier: no topological protection ...
![arXiv:1312.4758v2 [quant-ph] 10 Apr 2014](http://s1.studyres.com/store/data/021352507_1-d587dd4045ccae4ae6a47bb17173f358-300x300.png)
arXiv:1312.4758v2 [quant-ph] 10 Apr 2014
... k. Estimating the ground state energy of such a Hamiltonian is known as the k-local Hamiltonian problem [22, 21]. This problem is QM A-complete for any k ≥ 2 [21]. QM Acompleteness also holds if we assume a natural geometric structure on the particles, with particles arranged on a grid and each part ...
... k. Estimating the ground state energy of such a Hamiltonian is known as the k-local Hamiltonian problem [22, 21]. This problem is QM A-complete for any k ≥ 2 [21]. QM Acompleteness also holds if we assume a natural geometric structure on the particles, with particles arranged on a grid and each part ...
polarized quantum states
... Moreover, to generate the basis set we need only make geometrical rotations or differential phase shifts. Such orbits are of particular interest for experimentalists to implement 3dimensional quantum information protocols, and to demonstrate effects of twophoton interference. It can be shown that th ...
... Moreover, to generate the basis set we need only make geometrical rotations or differential phase shifts. Such orbits are of particular interest for experimentalists to implement 3dimensional quantum information protocols, and to demonstrate effects of twophoton interference. It can be shown that th ...
Phys. Rev. Lett. 98, 070602
... We also consider perturbing the system by coupling it to an Ohmic heat bath. When coupled to such a bath, a quantum mechanical degree of freedom can undergo a transition from coherent to incoherent behavior [8]. Recently, the effects of such a coupling on quantum phase transitions, at which divergen ...
... We also consider perturbing the system by coupling it to an Ohmic heat bath. When coupled to such a bath, a quantum mechanical degree of freedom can undergo a transition from coherent to incoherent behavior [8]. Recently, the effects of such a coupling on quantum phase transitions, at which divergen ...
Quantum computing
Quantum computing studies theoretical computation systems (quantum computers) that make direct use of quantum-mechanical phenomena, such as superposition and entanglement, to perform operations on data. Quantum computers are different from digital computers based on transistors. Whereas digital computers require data to be encoded into binary digits (bits), each of which is always in one of two definite states (0 or 1), quantum computation uses quantum bits (qubits), which can be in superpositions of states. A quantum Turing machine is a theoretical model of such a computer, and is also known as the universal quantum computer. Quantum computers share theoretical similarities with non-deterministic and probabilistic computers. The field of quantum computing was initiated by the work of Yuri Manin in 1980, Richard Feynman in 1982, and David Deutsch in 1985. A quantum computer with spins as quantum bits was also formulated for use as a quantum space–time in 1968.As of 2015, the development of actual quantum computers is still in its infancy, but experiments have been carried out in which quantum computational operations were executed on a very small number of quantum bits. Both practical and theoretical research continues, and many national governments and military agencies are funding quantum computing research in an effort to develop quantum computers for civilian, business, trade, and national security purposes, such as cryptanalysis.Large-scale quantum computers will be able to solve certain problems much more quickly than any classical computers that use even the best currently known algorithms, like integer factorization using Shor's algorithm or the simulation of quantum many-body systems. There exist quantum algorithms, such as Simon's algorithm, that run faster than any possible probabilistic classical algorithm.Given sufficient computational resources, however, a classical computer could be made to simulate any quantum algorithm, as quantum computation does not violate the Church–Turing thesis.