2,903 research outputs found
Pairs of k-step reachability and m-step observability matrices
No full textLet V and W be matrices of size n x pk and qm x n, respectively.
A necessary and sufficient condition is given for the existence of a triple (A,B,C) such that V is a k-step reachability matrix of (A,B) and W an m-step observability matrix of (A,C)
Josephson current via an isolated Majorana zero mode
No full textWe study the equilibrium dc Josephson current in a junction between an s-wave and a topological superconductor. Cooper pairs from the s-wave superconducting lead can transfer to the topological side either via an unpaired Majorana zero mode localized near the junction or via the above-gap continuum states. We find that the Majorana contribution to the supercurrent can be switched on when time-reversal symmetry in the conventional lead is broken, e.g., by an externally applied magnetic field inducing a Zeeman splitting. Moreover, if the magnetic field has a component in the direction of the effective spin-orbit field, there will be a Majorana-induced anomalous supercurrent at zero phase difference. These behaviors may serve as a signature characteristic of Majorana zero modes and are accessible to devices with only superconducting contacts.QRD/Wimmer GroupBUS/Quantum Delf
Monotonicity and parametrization results for continuous-time algebraic Riccati equations and Riccati inequalities
No full textWimmer, Harald K.. (1992). Monotonicity and parametrization results for continuous-time algebraic Riccati equations and Riccati inequalities. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/2209
On the existence of a least and negative-semidefinite solution of the discrete-time algebraic Riccati equation
No full textWimmer, Harald K.. (1992). On the existence of a least and negative-semidefinite solution of the discrete-time algebraic Riccati equation. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/2206
Order reduction of discrete-time algebraic Riccati equations with singular closed loop matrix
No full textWe study the general discrete-time algebraic Riccati equation and deal with the case where the closed loop matrix corresponding to an arbitrary solution is singular. In this case the extended symplectic pencil associated with the DARE has 0 as a characteristic root and the corresponding spectral deflating subspace gives rise to a subspace where all solutions of the DARE coincide. This allows for a reduction of the original DARE to an equation of smaller size
The approval books program in the HSU Library
No full textOyler, David K.; Wimmer, Ted. The approval books program in the HSU Library. In: Forum: a faculty and staff journal for Humboldt State University, v.3, no.2 (Spring 1981), p.9-10
Reachability matrices and cyclic matrices
No full textWe study reachability matrices R(A, b) = [b,Ab, . . . ,An−1b], where A is an n × n matrix over a field K and b is in Kn. We characterize those matrices that are reachability matrices for some pair (A, b). In the case of a cyclic matrix A and an n-vector of indeterminates x, we derive a factorization of the polynomial det(R(A, x))
A Comparison Theorem For Matrix Riccati Difference-equations
No full textDifference equations of the form X(t) = F*(t)X(t - 1)F(t) - F*(t)X(t - 1)G(t)[I + G*(t)X(t - 1)G(t)]-1G*(t)X(t - 1)F(t) + Q(t) and their associated Hermitian matrices H(t) = (Q(F)F*-GG*)(t) are studied. Solution Of different Riccati equations can be compared if the difference of their corresponding Hermitian matrices is semidefinite for all t. An application to the discrete-time LQ optimal control problem is given
- …
