Abstract The probability amplitudes for quantum entanglement, also known as Bell sates, are utilized to arrive explicitly at the identity matrix I and the
σx σx ,
σy σy , and
σz σz Pauli matrices, via a straight-forward
2×2 2×2 matrix representation that utilizes the vector direct product. It is also indicated that this approach is completely equivalent to the utilization of the Kronecker product
⊗ ⊗ to multiply the relevant ket vectors. Furthermore, it is shown that the polarization rotation matrix R, operating on the various versions of the probability amplitude for quantum entanglement, yields four identities elegantly interconnecting these probability amplitudes.
Matrices are widely, and extensively, used in quantum mechanics. Indeed, one of the avenues to quantum mechanics, that of Born, Heisenberg, and Jordan, is via matrices. One additional asset of matrices is that they are the natural mathematical language to describe quantum computing. Furthermore, matrices identify themselves in the physical tangible world via optical elements such as mirrors, beam splitters, polarization rotators, and interferometers. And these are the elements that comprise the hardware of photonic quantum computers. Here, we introduce the Pauli matrices https://www.w3.org/1998/Math/MathML" display="inline"> σ x , σ y , σ z , plus the identity matrix I , via the probability amplitudes of quantum entanglement. Once this is accomplished, we show how these matrices can be used to perform mathematical transformations, on quantum entanglement states, that form the bases of quantum computing as treated in the next chapter.
Following an introduction on interferometric physical computers, the discussion turns to Feynman’s contribution to quantum computing and qbits. The ψ + , ψ − , ψ + , and ψ − quantum entanglement states are expressed in terms of the σ x , σ y , σ z , and I matrices and the discussion continues, on quantitative terms, Pauli gates, the Hadamard gate, and the CNOT gate. The equivalence between σ x and the polarization rotational matrix R is noted. Interaction between the ψ + , ψ − , ψ + , and ψ − states, R and the Hadamard gate give rise to whole families of quantum mathematical operations. Physical representations for R and the Hadamard gate are explicitly identified.
We examine multiphoton interference with a symmetric
SU(N) beam splitter
SN, an extension of features of the
SU(2) 50/50 beam splitter extended Hong-Ou-Mandel (eHOM) effect, whereby one obtains a zero amplitude (probability) for the output coincidence state (defined by equal number of photons
n/N in each output port), when a total number
n of photons impinges on the
N-port device. These are transitions of the form
∣n1,n2,…,nN⟩→SN∣n/N⟩⊗N, where
n=∑i=1Nni, which generalize the Hong-Ou-Mandel (HOM) effect $|1,1\rangle \overset{S_2}{\to}|1,1\rangle $, the eHOM effect $|n_1,n_2\rangle \overset{S_2}{\to}|\tfrac{n_1+n_2}{2},\tfrac{n_1+n_2}{2}\rangle $, and the generalized HOM effect (gHOM)
∣1⟩⊗N→SN∣1⟩⊗N, which have previously been studied in the literature. The emphasis of this work is on illuminating how the overall destructive interference occurs in separate groups of destructive interferences of sub-amplitudes of the total zero amplitude. We develop symmetry properties for the generalized eHOM effect (geHOM)
∣n1,n2,…,nN⟩→SN∣n/N⟩⊗N involving a zero amplitude governed by Perm(
Λ)=0, for an appropriately constructed matrix
Λ(SN) built from the matrix elements of
SN. We develop an analytical constraint equation for Perm
(Λ) for arbitrary
N that allows us to determine when it is zero. We generalize the SU(2) beam splitter feature of central nodal line (CNL), which has a zero diagonal along the output probability distribution when one of the input states is of odd parity (containing only odd number of photons), to the general case of
N=2∗N′ where
N′∈odd.
Quantum mechanics explains the behavior of matter and its movement with energy in the scale of atoms and subatomic particles. In quantum circuits there are many gates such as Hadamard Gate, Pauli Gates, many more gates for half turns, quarter turns, eighth turns, sixteenth turns and so on, rest for spinning, parametrized etc. Linear operators in general and quantum mechanics can be represented in the form of vectors and in turn can be viewed as matrices format because linear operators are totally equivalent with the matrices view point. This paper discloses creation of various quantum matrices using Quantum bits. Square, Identity and Transposition of matrices are performed considering whole process in entanglement. Angle, phase, coordinates, magnitude, complex numbers and amplitude has been noted and documented in this paper for further research.