operation-annihilation

Currently Reading: Deadpool Volume 8 - Operation Annihilation HC

Collects: Deadpool (2008) #36-39, Deadpool (1997) #4

Deadpool returns to Earth after taking over Macho Gomez’s bounty hunting job last issue, to find himself face to face with everyone who wants to kill him. Again.
And then, Deadpool tries to provoke The Hulk into killing him!
I won’t be reading the classic, since I’ve read it before, and I don’t fancy it again right now.

arxiv.org
[1602.02166] Numerical Study of the Simplest String Bit Model

[ Authors ]
Gaoli Chen, Songge Sun
[ Abstract ]
String bit models provide a possible method to formulate string as a discrete chain of point-like string bits. When the bit number $M$ is large, a chain behaves as a continuous string. We study the simplest case that has only one bosonic bit and one fermionic bit. The creation and annihilation operators are adjoint representations of $U\left(N\right)$ color group. We show that the supersymmetry reduces the parameter number of a Hamiltonian from seven to three and, at $N=\infty$, ensures continuous energy spectrum, which implies the emergence of one spatial dimension. The Hamiltonian $H_{0}$ is constructed so that in large $N$ limit it produces a worldsheet spectrum with one grassmann worldsheet field. We concentrate on numerical study of the model in finite $N$. For the Hamiltonian $H_{0}$, we find that the would-be ground energy states disappear at $N=\left(M-1\right)/2$ for odd $M\leq11$. Such a simple pattern is spoiled if $H$ has an additional term $\xi\Delta H$ which does not affect the result of $N=\infty$. The disappearance point moves to higher (lower) $N$ when $\xi$ increases (decreases). Particularly, the $\pm\left(H_{0}-\Delta H\right)$ cases suggest a possibility that the ground state could survive at large $M$ and $M\gg N$. Our study reveals that the model has stringy behavior: when $N$ is fixed and large enough, the ground energy decreases linearly with respect to $M$ and the excitation energy is roughly of order $M^{-1}$. We also verify that a stable system of Hamiltonian $\pm H_{0}+\xi\Delta H$ requires $\xi\geq\mp1$.

arxiv.org
[1602.00008] New class of quantum error-correcting codes for a bosonic mode

[ Authors ]
Marios H. Michael, Matti Silveri, R. T. Brierley, Victor V. Albert, Juha Salmilehto, Liang Jiang, S. M. Girvin
[ Abstract ]
We construct a new class of quantum error-correcting codes for a bosonic mode which are advantageous for applications in quantum memories, communication, and scalable computation. These `binomial quantum codes’ are formed from a finite superposition of Fock states weighted with binomial coefficients. The binomial codes can exactly correct errors that are polynomial up to a specific degree in bosonic creation and annihilation operators, including amplitude damping and displacement noise as well as boson addition and dephasing errors. For realistic continuous-time dissipative evolution, the codes can perform approximate quantum error correction to any given order in the timestep between error detection measurements. We present an explicit approximate quantum error recovery operation based on projective measurements and unitary operations. The binomial codes are tailored for detecting boson loss and gain errors by means of measurements of the generalized number parity. We discuss optimization of the binomial codes and demonstrate that by relaxing the parity structure, codes with even lower unrecoverable error rates can be achieved. The binomial codes are related to existing two-mode bosonic codes but offer the advantage of requiring only a single bosonic mode to correct amplitude damping as well as the ability to correct other errors. Our codes are similar in spirit to `cat codes’ based on superpositions of the coherent states, but offer several advantages such as smaller mean number, exact rather than approximate orthonormality of the code words, and an explicit unitary operation for repumping energy into the bosonic mode. The binomial quantum codes are realizable with current superconducting circuit technology and they should prove useful in other quantum technologies, including bosonic quantum memories, photonic quantum communication, and optical-to-microwave up- and down-conversion.

arxiv.org
[1602.01280] Quantum optical dipole radiation fields

[ Authors ]
Adam Stokes
[ Abstract ]
We introduce quantum optical dipole radiation fields defined in terms of photon creation and annihilation operators. These fields are identified through their spatial dependence, as the components of the total fields that survive infinitely far from the dipole source. We use these radiation fields to perturbatively evaluate the electromagnetic radiated energy-flux of the excited dipole. Our results indicate that the standard interpretation of a bare atom surrounded by a localised virtual photon cloud, is difficult to sustain, because the radiated energy-flux surviving infinitely far from the source contains virtual contributions. It follows that there is a clear distinction to be made between a radiative photon defined in terms of the radiation fields, and a real photon, whose identification depends on whether or not a given process conserves the free energy. This free energy is represented by the difference between the total dipole-field Hamiltonian and its interaction component.