Emulation of quantum and quantum-inspired spectrum analysis and superposition with classical transconductor-capacitor circuits

Patent metadata

Field	Value
Publication number	US-10204199-B2
Application number	US-201715826115-A
Country	US
Kind code	B2
Filing date	Nov 29, 2017
Priority date	Nov 29, 2016
Publication date	Feb 12, 2019
Grant date	Feb 12, 2019

Abstract

We disclose transconductor-capacitor classical dynamical systems that emulate quantum dynamical systems and quantum-inspired systems by composing them with 1) capacitors that represent ℏ termed Planck capacitors; 2) a ‘quantum admittance’ element, which can be emulated efficiently via coupled transconductors; 3) an emulated ‘quantum transadmittance element’ that can couple emulated quantum admittances to each other; and 4) an emulated ‘quantum transadmittance mixer element’ that can couple emulated quantum admittances to each other under the control of an input. We describe a ‘Quantum Cochlea’, a biologically-inspired quantum traveling-wave system with coupled emulated quantum two-state systems for efficient spectrum analysis that uses all of these parts. We show how emulated quantum transdmittance mixers can help represent an exponential number of quantum superposition states in the spectral domain with linear classical resources, even if they are not all simultaneously accessible as in actual quantum systems.

First claim

What is claimed is:

1. A classical circuit architecture for representing and storing a superposition of 2 N quantum states as a spectrum of two real and imaginary output classical signals with said architecture needing circuit hardware resources proportional to N+1 comprising N emulated quantum two-state systems, indexed by k=0, 1, 2, 3, . . . N, with each said two-state system with two emulated quantum admittance circuits with quantum admittance values of +iE 0 2 k and −iE 0 2 k whose complex outputs are summed to architect a superposition of two states within each two-state system and then mixed, in a complex mixer, with analogous superposed signals from the corresponding two-state system with index k+1 such that the resulting mixed signal creates a new signal that represents a superposition of 2 k+1 states at distinguishable frequency locations, which may then be used to re-initiate this process in a recursive fashion such that if the said recursive process is initiated at k=0 and terminated at k=N−1, the final output signals will represent a superposition of 2 N quantum states.

2. The circuit architecture of claim 1 wherein the probability of the two states of each of the emulated two-state quantum systems of any index k is ½ such that the superposition of all 2 N quantum states in the final output signal has an equally balanced probability amongst all states.

3. The circuit architecture of claim 1 wherein the initial condition probability amplitudes of the states of each emulated two-state quantum system with index k are transiently established with the use of emulated transadmittance mixer circuits and an emulated two-state system and configured with a control input resonant with the energy difference between the two states corresponding to k such that N+1 resonant control inputs can transiently couple all the two emulated quantum admittance circuits within a two-state system to establish or alter their initial conditions but then be subsequently turned off, thus enabling emulation of write capability that also scales with N+1 hardware resources.

4. The circuit architecture of claim 1 wherein any of the k=0, 1, 2, . . . N−1 output signals from successive stages of the recursive architecture are fed to a quantum cochlea circuit such that the emulated quantum states of the superposition may be efficiently spectrally analyzed and measured, without destroying the superposition as would occur in an actual quantum system.

5. The circuit architecture of claim 1 wherein any emulated quantum admittances connected to C HBAR capacitors are replaced by oscillators architected to have input-output behavior and dynamics that are functionally like in whole or in part as that exhibited by the emulated quantum-admittances and C HBAR capacitors but are not constructed by the same means.

6. The complex mixer used in the circuit architecture of claim implemented with a complex transadmittance mixer circuit in a voltage-in-voltage-out mode or with the output currents of the mixer converted to voltages via classical impedance circuit elements.

7. The circuit architecture of claim 1 where a different set of exponentially spaced E k are used, with the exponential radix not necessarily being 2.

8. The circuit architecture of claim 1 where a different set of E k are used but with the E k still sufficiently different from one another such that all quantum-state superposition information in the spectral domain is preserved by one or more cascaded complex mixing operations.

9. The circuit architecture of claim 1 wherein the initial-condition probability amplitudes of the states of each emulated two-state quantum system with index k are transiently established with a means for initializing or writing values for its state variables, said means comprising a circuit architecture that is composed of 2(N+1) emulated quantum-admittance circuits attached to C HBAR capacitors indexed by k=0, 1, 2, . . . N with quantum admittance energies of −iE 0 2 k and +iE 0 2 k at each k and 2(N+1) associated emulated quantum transadmittance mixer circuits, said mixer circuits all receiving a classical signal V in at one of their real or imaginary inputs, and mixing it with complex real-and-imaginary signals output by said emulated quantum admittances to create current outputs that are averaged on a capacitor for a fixed period of time to create 4(N+1) quadrature real and imaginary output signals that encode spectral information about V in in these outputs.

10. The circuit architecture of claim 9 wherein the averaging capacitors are replaced by leaky capacitors with time constant RC such than an analog continuous running average may be obtained.

11. The circuit architecture of claim 9 wherein the emulated quantum admittance circuits are identical to those in the circuit architecture whose state variables it is writing or initializing such that common circuits in both circuit architectures can be shared via multiplexing.

12. The circuit architecture of claim 1 wherein any of the k=0, 1, 2, . . . N−1 output signals from successive stages of the recursive architecture are fed to a circuit such that the emulated quantum states of the superposition may be spectrally analyzed and measured, without destroying the superposition as would occur in an actual quantum system.

13. The circuit architecture of claim 1 wherein the same emulated quantum two-state systems are used to both create superposition states as well as to perform quantum or quantum-inspired computing.

Assignees

• Dartmouth College

Inventors

• Sarpeshkar Rahul

Classifications

• G06N7/01

  Probabilistic graphical models, e.g. probabilistic networks · CPC title

• G06F30/367

  Design verification, e.g. using simulation, simulation program with integrated circuit emphasis [SPICE], direct methods or relaxation methods · CPC title

• H03H11/0422

  using transconductance amplifiers, e.g. gmC filters · CPC title

• H03H11/1204

  Distributed RC filters · CPC title

• G06F7/48

  using non-contact-making devices, e.g. tube, solid state device; using unspecified devices · CPC title