Quantum cochlea for efficient spectrum analysis

Patent metadata

Field	Value
Publication number	US-10248748-B2
Application number	US-201816178764-A
Country	US
Kind code	B2
Filing date	Nov 2, 2018
Priority date	Nov 29, 2016
Publication date	Apr 2, 2019
Grant date	Apr 2, 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, and how the quantum cochlea is a very efficient spectrum analyzer for non-destructive readout of these spectral-domain signals.

First claim

What is claimed is:

1. A Quantum Cochlea circuit for spectral analysis of an input comprised of an abutting cascade of topologically identical emulated quantum two-state systems with transadmittance mixers, each configured with an exponentially decreasing taper in the difference between their high-energy and low-energy emulated-quantum-admittance transconductance values as one proceeds along the cochlear cascade, and with a sequential alternation in their orientation such that only compatibly similar high-energy admittances or only compatibly similar low-energy admittances abut each other when two cochlear stages join.

2. The quantum cochlear circuit of claim 1 wherein the forward-propagation transadmittance value of the quantum cochlear stage along the cascade is made slightly higher than that of the backward-propagation transadmittance value of the quantum cochlear stage such that reflections of traveling waves along the cascade are minimized.

3. The quantum cochlear circuit of claim 1 wherein a probability pattern recognition circuit is used on the outputs of the cochlear cascade to improve its spectral analysis capabilities.

4. The quantum cochlear circuit of claim 1 wherein the modulation frequency at any spectral output of the Quantum Cochlea is measured to obtain amplitude information about the cochlear input.

5. The quantum cochlear circuit of claim 1 wherein the location of maximum response at any spectral output of the Quantum Cochlea is measured to obtain frequency information about the cochlear input.

6. An implementation of the quantum cochlear circuit of claim 1 in physical quantum hardware where physical quantum two-state systems such as atoms, electrons, ions, spins, or Josephson junctions with different energy levels replace the quantum admittance emulation circuits, and correspondingly electromagnetic waves, electric, or magnetic fields, or voltages serve as the cochlear input, and said atoms, electrons, ions, spins, or Josephson junctions are coupled to each other via approximately-nearest-neighbor coupling in an exponentially tapered fashion to create the cochlear cascade.

7. The quantum cochlear circuit of claim 1 that incorporates gain-control computations or circuits to achieve wide dynamic range via any means involving nonlinearity, parametric amplification, parametric attenuation, or controlled instability.

8. The quantum cochlear circuit of claim 7 wherein inputs that determine the gain of the gain-control circuits or computations arise from sensing the modulation frequency of the cochlear outputs.

9. The quantum cochlear circuit of claim 3 with a specific probability pattern-recognition circuit comprised of a set of 3 paired inputs (R 1 ,I 1 ), (R 2 , I 2 ), (R 3 , I 3 ) each corresponding to the real and imaginary parts of a complex signal, from which a squared-sum probability-like measure, p 1 =R 1 2 +I 1 2 , p 2 =R 2 2 +I 2 2 , p 3 =R 3 2 +I 3 2 of each of these signals, is computed inside said circuit, an output current that is proportional to (1−p 1 )p 2 (1−p 3 ) is generated via a multiplicative transconductance circuit, and said current is filtered by a parallel RC circuit to generate an output voltage that is largest when patterns of correlated probability in the input that follow a Low-High-Low pattern are dominant with 1/RC determining the averaging bandwidth for estimating such correlations.

10. The circuit of claim 9 wherein other multiplicative patterns of correlated probability amongst the inputs such as p 1 p 2 p 3 or (1−p 1 )p 2 in a High-High-High or Low-High-Neutral pattern respectively or any other combinatorial such combination of 3 inputs is estimated by altering the multiplicative design of only the transconductance portion of the circuit.

11. The N-input generalization of the circuit of claim 9 when N pairs with index (R i , I i ) are input to the circuit and a desired pattern of High, Low, or Neutral probability emphasis for this pair is architected by having the transconductance output current altered to include a multiplicative term of value p i , (1-p i ), or 1 respectively in its N-product-dependent output with i spanning from 1 to N for each such input pair.

Assignees

• Dartmouth College

Inventors

• Sarpeshkar Rahul

Classifications

• G06N7/01

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

• H03H11/0422

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

• G05F3/262

  using field-effect transistors only · CPC title

• G06N20/00

  Machine learning · CPC title

• G06F30/367

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